In the Supreme Court of the United States
STATE OF ARIZONA, PETITIONER
RODNEY JOSEPH GANT
ON WRIT OF CERTIORARI
TO THE SUPREME COURT OF ARIZONA
BRIEF FOR THE UNITED STATES
AS AMICUS CURIAE SUPPORTING PETITIONER
PAUL D. CLEMENT
Counsel of Record
ALICE S. FISHER
Assistant Attorney General
MICHAEL R. DREEBEN
Deputy Solicitor General
ANTHONY A. YANG
Assistant to the Solicitor
JOSEPH F. PALMER
Department of Justice
Washington, D.C. 20530-0001
Does the Fourth Amendment require law enforce ment officers to demonstrate a threat to their safety or a need to preserve evidence related to the crime of ar rest in order to justify a warrantless vehicular search in cident to arrest conducted after the vehicle's recent oc cupants have been arrested and secured?
In the Supreme Court of the United States
STATE OF ARIZONA, PETITIONER
RODNEY JOSEPH GANT
ON WRIT OF CERTIORARI
TO THE SUPREME COURT OF ARIZONA
BRIEF FOR THE UNITED STATES
AS AMICUS CURIAE SUPPORTING PETITIONER
INTEREST OF THE UNITED STATES
This case presents the question whether law enforce ment officers must demonstrate a threat to their safety or a need to preserve evidence related to the crime of arrest in order to justify a warrantless search of a car incident to arrest, after the car's recent occupants have been arrested and secured. The resolution of that ques tion will affect the practices of federal law enforcement officers in the commonly recurring situation in which the recent occupant of a vehicle is arrested. In addition, it will affect the admissibility in federal prosecutions of evidence obtained by federal, state, or local law enforce ment agents as the result of the search of an automobile incident to the lawful arrest of an individual who has recently occupied the vehicle. The United States there fore has a substantial interest in this case, and indeed has participated in previous cases presenting this issue. See, e.g., Thornton v. United States, 541 U.S. 615 (2004); New York v. Belton, 453 U.S. 454 (1981).
1. On August 25, 1999, two Tucson, Arizona, police officers responded to a report of possible drug activity at a residence. Respondent answered the door, identi fied himself, and told the officers that the homeowner would return later that day. The officers left. They sub sequently ran a records check on respondent and discov ered that his driver's license was suspended and that he had an outstanding arrest warrant for driving on a sus pended license. J.A. 151-152.
The officers returned to the house that night. They encountered a man outside the house and, soon thereaf ter, made contact with a woman sitting in a parked car. After speaking with those individuals, the officers ar rested the woman for possession of a crack pipe and the man for providing a false name to the officers. Both were handcuffed and placed in locked patrol cars. J.A. 145, 152; Pet. App. B5; see J.A. 48-50, 60, 81, 108.
As officers placed the two individuals into patrol cars, respondent returned to the scene driving a car. Respondent entered the driveway for the residence, pas sing within a few feet of an officer, who shined his flash light into the passenger compartment and recognized respondent from earlier in the day. That officer immedi ately summoned respondent as he got out of his car and, after respondent walked approximately 8-12 feet to meet the officer, placed respondent under arrest for the out standing warrant and for driving with a suspended li cense. The officer handcuffed respondent and placed him in a locked patrol car, where respondent remained under the supervision of that officer. By that time, a total of four or five officers were at the scene. While officers had been told that the homeowner might return, the homeowner had yet to appear. J.A. 145-146, 148- 149, 152; Pet. App. B5, B9 n.4; see J.A. 51-58, 61, 71-72, 77-79, 100, 114, 119.
Two officers immediately searched the passenger compartment of respondent's car and discovered a hand gun and a baggie containing cocaine. After the search was completed, respondent's vehicle was towed to a po lice station and impounded. Respondent was charged with one count of possessing narcotics for sale and one count of possessing drug paraphernalia. J.A. 152; see J.A. 61-63, 70, 98, 129.
2. Respondent moved to suppress the evidence found in his vehicle, but the Arizona Superior Court de nied his pretrial motion. J.A. 37-39, 43. A jury subse quently found respondent guilty on both counts and, in October 2000, the court imposed a three-year sentence of imprisonment. Pet. App. B4; J.A. 2. The Arizona Court of Appeals reversed respondent's convictions, holding that his suppression motion should have been granted because the police did not make contact with respondent until after he had exited his vehicle. State v. Gant, 43 P.3d 188, 194 (Ariz. App. 2002). The Arizona Supreme Court denied review, J.A. 153, and this Court granted the State's petition for a writ of certiorari. Ari zona v. Gant, 538 U.S. 976 (2003).
The Arizona Supreme Court subsequently decided State v. Dean, 76 P. 3d 429 (Ariz. 2003), which abrogated the rule adopted by the court of appeals in this case, concluding that the police may search a car incident to arrest even if they initiate contact with the arrestee af ter he has exited the vehicle. See id. at 434-437 (discuss ing Gant, 43 P.3d 188). This Court accordingly vacated the judgment of the Arizona Court of Appeals in this case and remanded for reconsideration in light of Dean. Arizona v. Gant, 540 U.S. 963 (2003).
Because the trial court had addressed the search of respondent's car based on stipulated facts rather than testimony, the court of appeals remanded for an eviden tiary hearing. Pet. App. B4-B5. After conducting hear ings, J.A. 44-142, the trial court again upheld the search. J.A. 143-149. The court concluded that the search was incident to respondent's arrest because the police ar rested him seconds after he got out of the car and searched his car immediately after that arrest. J.A. 148- 149.
Respondent again appealed to the Arizona Court of Appeals, which reversed in a divided opinion. Pet. App. B1-B23. The majority held that the search of respon dent's vehicle violated the Fourth Amendment because it was not contemporaneous with respondent's arrest and did not satisfy the rationale for a search incident to arrest under Chimel v. California, 395 U.S. 752 (1969). Pet. App. B14-B15; see J.A. 153.
3. The Arizona Supreme Court granted the State's petition for review and, in a 3-2 decision, affirmed the judgment of the court of appeals while vacating its opin ion. J.A. 154, 166-167. The majority held that the search of respondent's car violated the Fourth Amendment be cause it was not justified by the search-incident-to-ar rest exception to the Fourth Amendment's warrant re quirement. J.A. 166. The court explained that this Court in Chimel justified that exception based on the twin "rationales of officer safety and preservation of evi dence," and that Chimel therefore limited the scope of a search incident to arrest to the suspect's person and "the area 'within his immediate control,'" that is, the "area from within which he might gain possession of a weapon or destructible evidence." J.A. 155 (quoting Chimel, 395 U.S. at 763).
In the court's view, this Court's subsequent decision in New York v. Belton, 453 U.S. 454 (1981), merely de fined the "permissible scope" of an "otherwise lawful search of an automobile incident to arrest." J.A. 156. On that view, Belton established only a bright-line rule that the area within the arrestee's immediate control will include the vehicle's passenger compartment and the containers within that compartment. Ibid. The ma jority concluded that Belton did not address "the thresh old question whether the police may conduct a search incident to arrest at all." J.A. 156-157. The court an swered that question by holding that, under Chimel, such a search must be supported on a case-by-case basis by "determin[ing] whether officer safety or the preser vation of evidence" actually justified the search. Ibid. The court concluded that a search cannot be justified if the "totality of the circumstances" indicates that "an arrestee is secured and thus presents no reasonable risk to officer safety or the preservation of evidence." J.A. 165-166.
Applying that test, the court held that the search of respondent's car was unjustified because it was not "necessary to protect the officers at the scene or prevent the destruction of evidence." J.A. 160. It emphasized that, when the search began, respondent and the other two arrestees at the scene were handcuffed and placed in the back of locked patrol cars; at least four officers were present, including one officer supervising respon dent; and no unsecured civilians had been identified in the vicinity. J.A. 157. Under those circumstances, the court concluded that "the police had no reason to be lieve" that their safety was at risk or that anyone could gain access to respondent's vehicle. Ibid. The court accordingly held that the search was not a lawful search incident to arrest because neither Chimel rationale spe cifically applied to this case. Ibid.
The court acknowledged that it was "possible" to interpret Belton's bright-line rule as dispensing with the need for the police to "assess the exigencies" surround ing each custodial arrest. JA. 158. It likewise recog nized that, in Thornton v. United States, 541 U.S. 615 (2004), this Court upheld a search on facts that "resem ble" the facts in this case, JA. 160-162, and that "most other courts * * * have found Belton and Thornton dispositive of the question whether a search like the one at issue was incident to arrest." J.A. 162. The majority nevertheless believed that neither Belton nor Thornton addressed the "precise question" whether a vehicle search is incident to arrest if the Chimel justifications "no longer exist at the time of the search." J.A. 163.
Two justices dissented. J.A. 167-176. They con cluded that the majority opinion conflicted with Belton's bright-line rule, which neither depended on a "case-spe cific determination that there may be weapons or evi dence in the automobile" nor required that the "pres ence of the Chimel rationales" be established in every case. J.A. 169-170. The dissenters noted that the New York state-court decision that Belton reversed and Jus tice Brennan's dissent in Belton both advanced the very argument that the majority had adopted, and that Belton had rejected it. J.A. 170-172. In addition, they concluded that the majority's case-by-case approach requiring the demonstrated presence of the Chimel ra tionales for every arrest conflicted with Belton's intent to establish a "straightforward rule" that would guide officers in the field and avoid after-the-fact, "case-by- case adjudication" of the risk to officers or evidence. J.A. 173-174.
SUMMARY OF ARGUMENT
In Belton, this Court adopted a bright-line rule to guide the officer in the field when the recent occupant of a vehicle is arrested: the officer may search the passen ger compartment of the vehicle that the arrestee re cently occupied as a contemporaneous incident of a law ful custodial arrest. The Arizona Supreme Court's deci sion in this case effectively overturns the Belton rule by converting it into a totality of the circumstances inquiry that asks whether, on the facts of a particular case, a search was necessary to protect officer safety or to pre serve evidence. That case-specific approach provides officers with little practical guidance and should be re jected.
This Court's search-incident-to-arrest doctrine rests on the general need to protect officers from potential harm and to preserve evidence "whenever officers effect a custodial arrest" of the recent occupant of a vehicle. Michigan v. Long, 463 U.S. 1032, 1049 n.14 (1983). A custodial arrest is a volatile and dangerous event, with heightened risks that a suspect will grab for a weapon or attempt to conceal or destroy evidence of his guilt. This Court has thus long held that a search incident to arrest is per se reasonable regardless of whether the circum stances of the particular case involve one of the twin rationales for such a search. See United States v. Rob inson, 414 U.S. 218, 235 (1973). Both Belton and Thorn ton reaffirmed that principle. Indeed, the Court in Thornton upheld a vehicle search that was conducted after the defendant was handcuffed and secured in a patrol car. The Arizona Supreme Court's rule requiring a showing that each particular case involved a threat to officer safety or a risk of evidence destruction directly conflicts with more than three decades of this Court's precedents.
Under Belton and Thornton, the search of respon dent's vehicle was valid. Respondent was a "recent occu pant" of the car, he was subjected to a "lawful custodial arrest" next to the car, and the search of respondent's car was conducted as "a contemporaneous incident of that arrest." Belton, 453 U.S. at 460. Moments after respondent exited his vehicle, the police arrested him and promptly searched that vehicle in one continuous process.
The Arizona Supreme Court's decision eliminates the bright line drawn by Belton and incorrectly replaces it with an ad hoc, case-by-case approach that Belton itself found to be unworkable. Belton specifically recognized that it was "essential" to provide officers in the field with a "single familiar standard" for determining when the search of a car is authorized incident to an arrest. 453 U.S. at 458 (quoting Dunaway v. New York, 442 U.S. 200, 213-214 (1979)). The Arizona Supreme Court's deci sion undermines that important objective by transform ing a bright-line rule into a totality-of-the-circumstances test for determining whether a threat to officer safety or a need to preserve evidence in any particular case suffi ciently justifies each search. J.A. 165-166. That inquiry accordingly reintroduces the very uncertainty and line-drawing difficulties that this Court sought to elimi nate in Belton.
Belton has built-in limitations that have proved to be clear and workable. Belton applies only in the case of the lawful arrest of a vehicle's "recent occupant" and only with respect to vehicle searches conducted as a "contemporaneous incident" to such an arrest. 453 U.S. at 460. A further narrowing of Belton to cases in which the police reasonably believe that evidence of the crime of arrest will be found in the vehicle makes little sense. Not only is such a recharacterization inconsistent with the Court's reasoning in Belton, it would disregard the officer-safety considerations that support Belton's bright-line rule. It would also effectively render Belton superfluous because the automobile exception to the warrant requirement already authorizes vehicle search es based on probable cause. Indeed, imposing such a limitation on Belton would create irreconcilable tension with Belton's existing limitations, which were developed consistent with Belton's original rationale. Accordingly, the Court should reaffirm Belton's bright-line rule au thorizing a search of a vehicle's passenger compartment as a contemporaneous incident to the arrest of the vehi cle's recent occupant.
A SEARCH OF A VEHICLE INCIDENT TO THE LAWFUL CUSTODIAL ARREST OF THE VEHICLE'S RECENT OCCU PANT IS LAWFUL EVEN WHEN THE ARRESTEE IS SE CURED IN A PATROL CAR AT THE TIME OF THE SEARCH
A. Belton Authorizes The Warrantless Search Of A Vehi cle's Passenger Compartment Where The Search Is A Contemporaneous Incident Of The Lawful Custodial Arrest Of The Vehicle's Recent Occupant
1. The Fourth Amendment to the Constitution guar antees that "[t]he right of the people to be secure in their persons, houses, papers, and effects, against un reasonable searches and seizures, shall not be violated," and further provides that "no Warrants shall issue, but upon probable cause." U.S. Const. Amend. IV. This Court has long recognized that when officers have made a lawful arrest, a search of the person of the arrestee and area within his control "is not only an exception to the warrant requirement of the Fourth Amendment, but is also a 'reasonable' search under that Amendment." United States v. Robinson, 414 U.S. 218, 235 (1973); see Weeks v. United States, 232 U.S. 383, 392 (1914).
Two longstanding rationales support the search- in cident-to-arrest doctrine: the need "to remove any weap ons that the [arrestee] might seek to use in order to re sist arrest or effect his escape," and the need to prevent the "concealment or destruction" of evidence. Chimel v. California, 395 U.S. 752, 763 (1969); see Knowles v. Iowa, 525 U.S. 113, 116-117 (1998) (citing cases). Both rationales address practical difficulties generally associ ated with custodial arrests. Indeed, this Court has re peatedly recognized that custodial arrests are highly volatile and dangerous events. See, e.g., id. at 117; Rob inson, 414 U.S. at 234-235 & n.5. In 2006 alone, 9233 law enforcement officers were assaulted and 12 of the 48 officers feloniously killed in the line of duty were mor tally wounded while attempting arrests. FBI, U.S. Dep't of Justice, Uniform Crime Reports: Law Enforce ment Officers Killed and Assaulted, Tables 19, 66 (2006) <http://www.fbi.gov/ucr/killed/2006/index.html> (Uni form Crime Reports); see FBI, U.S. Dep't of Justice, Killed in the Line of Duty: A Study of Felonious Kill ings of Law Enforcement Officers 3 (Sept. 1992). That is consistent with a well-established and dangerous pat tern. Between 1997 and 2006, 133 of the 562 law en forcement officers who were feloniously killed in the line of duty were slain in arrest situations, making the arrest by far the most dangerous situation that officers rou tinely confronted in that period. Uniform Crime Re ports, Table 19 (2006). In addition, the moment that an individual is placed under formal arrest, he has an in creased motive "to take conspicuous, immediate steps to destroy incriminating evidence." Cupp v. Murphy, 412 U.S. 291, 296 (1973).
This Court accordingly has recognized that, "[w]hen an arrest is made, it is reasonable for the arresting offi cer to search the person arrested in order to remove any weapons that the latter might seek to use in order to resist arrest or effect his escape," and "to search for and seize any evidence on the arrestee's person in order to prevent its concealment or destruction." Chimel, 395 U.S. at 762-763. Further, the officer's need to pro tect himself and to preserve evidence justifies a search of the area within the arrestee's "immediate control," which the Court has described as "the area from within which [the arrestee] might gain possession of a weapon or destructible evidence." Id. at 763.
Because "potential dangers lurk in all custodial ar rests," United States v. Chadwick, 433 U.S. 1, 14-15 (1977), the validity of a search incident to arrest "does not depend on what a court may later decide was the probability in a particular arrest situation that weapons or evidence would in fact be found." Robinson, 414 U.S. at 235. Instead, "[i]t is the fact of the lawful arrest which establishes the authority to search." Ibid.
2. In New York v. Belton, 453 U.S. 454 (1981), this Court applied those principles to define the permissible scope of a search incident to the arrest of the occupant of an automobile. Belton arose when a state trooper stopped a car for speeding and thereafter developed probable cause to arrest the occupants for possession of marijuana. The officer ordered the occupants out of the car and placed them under arrest. Id. at 455-456. After "patt[ing] down" the arrestees and separating them, the officer searched the passenger compartment of the car and discovered cocaine. Id. at 456. The state courts suppressed that evidence on the ground that, when the search took place, "there [was] no longer any danger that the arrestee or a confederate might gain access to the article." Ibid. This Court reversed. Id. at 463.
The Court began by noting the principle that "a law ful custodial arrest creates a situation which justifies the contemporaneous search without a warrant of the per son arrested and of the immediately surrounding area" from "within which [an arrestee] might gain possession of a weapon or destructible evidence." Belton, 453 U.S. at 457-458. The Court then explained that courts had struggled in applying that doctrine to the recurring question presented in Belton, namely, "whether, in the course of a search incident to the lawful custodial arrest of the occupants of an automobile, police may search inside the automobile after the arrestees are no longer in it." Id. at 459. As the Court recognized, the lower courts were in "disarray" on that issue and had "found no workable definition of 'the area within the immediate control of the arrestee' when that area arguably includes the interior of an automobile and the arrestee is its re cent occupant." Id. at 459-460 & n.1 (citation omitted).
The Court concluded that a "single familiar standard is essential to guide police officers, who have only lim ited time and expertise to reflect on and balance the so cial and individual interests involved in the specific cir cumstances they confront." Belton, 453 U.S. at 458 (ci tation omitted). "[T]o establish the workable rule [that] this category of cases requires," the Court adopted "the generalization that articles inside the relatively narrow compass of the passenger compartment of an automobile are in fact generally, even if not inevitably, within 'the area into which an arrestee might reach in order to grab a weapon or evidentiary ite[m].'" Id. at 460 (quoting Chimel, 395 U.S. at 763). Based on that generalization, the Court held that whenever "a policeman has made a lawful custodial arrest of the occupant of an automobile, he may, as a contemporaneous incident of that arrest, search the passenger compartment of that automobile." Ibid. (footnotes omitted).
The Belton Court emphasized that this rule, "while based upon the need to disarm and to discover evidence, does not depend on what a court may later decide was the probability in a particular arrest situation that weapons or evidence would in fact be found." 453 U.S. at 461 (quoting Robinson, 414 U.S. at 235). In fact, it specifically recognized that the search could extend to containers that "could hold neither a weapon nor evi dence of the criminal conduct for which the suspect was arrested." Ibid. Just as is true with respect to the search of the person of the arrestee, if the arrest is law ful, then the "search [of the vehicle] incident to the ar rest requires no additional justification." Ibid. (quoting Robinson, 414 U.S. at 235). In subsequent cases, this Court has specifically recognized the "bright-line" na ture of Belton's search-incident-to-arrest rule. See Florida v. Thomas, 532 U.S. 774, 776 (2001); Long, 463 U.S. at 1035 n.1, 1049 n.14 (1983).
3. In Thornton v. United States, 541 U.S. 615 (2004), the Court recently reaffirmed Belton's bright-line rule in a factual context closely paralleling the present case. The officer in Thornton made contact with Thornton immediately after he exited his car, noticed a bulge in Thornton's pocket, and asked Thornton whether he was carrying narcotics. Id. at 618. Thornton confessed that he was, and he pulled marijuana and crack cocaine out of his pockets. Ibid. The officer arrested him, hand cuffed him, secured him in a patrol car, and subsequent ly searched Thornton's vehicle, where he found a hand gun. Ibid.
The Court upheld the search, confirming that Belton established a "clear," "bright-line" rule that authorizes the search of a vehicle's passenger compartment inci dent to arrest "[s]o long as an arrestee is the sort of 're cent occupant' of the vehicle as [Thornton] was." Thorn ton, 541 U.S. at 623-624 & n.3. The Court recognized that it was "unlikely in this case" that the handcuffed arrestee could have returned to the passenger compart ment and grabbed his gun, but concluded that "the fire arm and the passenger compartment in general were no more inaccessible than were the contraband and the passenger compartment in Belton." Id. at 622. The Court emphasized that "[e]xperience has shown" the need for a "clear rule, readily understood by police offi cers" in the field that does "not depend on differing estimates of what items were or were not within reach of an arrestee at any particular moment." Id. at 622-623. The Court accordingly ruled that "[o]nce an officer de termines that there is probable cause to make an arrest, it is reasonable to allow officers to ensure their safety and to preserve evidence by searching the entire passen ger compartment." Id. at 623.
4. These precedents demonstrate that the search of respondent's vehicle was valid. Indeed, the relevant facts in this case are virtually indistinguishable from those surrounding the search upheld in Thornton. There is no doubt that respondent was a recent occupant of his vehicle, because the police contacted him immedi ately after he got out of his car, when he was still within 8-12 feet of it. J.A. 152. It is also clear that the search was a "contemporaneous incident" of respondent's law ful arrest. The arrest and search were a single, uninter rupted, and rapid transaction of events. "Within min utes" of making contact with respondent, the officers had arrested him, handcuffed him, and placed him in the patrol car, and the search began immediately thereafter. Ibid.
Respondent contends (Br. in Opp. 16-19) that the search was not substantially contemporaneous with re spondent's arrest, despite the facts that the search was performed within six minutes of the arrest and respon dent remained on the scene throughout the search, be cause the scene was secure and the arrest was complete. According to this argument, the question whether a search is incident to an arrest depends not on whether the arrest and search are contemporaneous as a matter of time and space but rather on the relative security of the arrest scene.
This Court, however, has traditionally analyzed this question primarily along the dimensions of time and space, factors that are much more susceptible to objec tive measurement than "relative security." See, e.g., Chadwick, 433 U.S. at 15 (search conducted long after defendant was taken into custody was not incident to arrest); Preston v. United States, 376 U.S. 364, 367 (1964) (search cannot be incident to arrest if it is remote in time from the arrest). The test for whether a search is contemporaneous with an arrest thus does not turn on whether the arrest scene is sufficiently secure at the time of the search, but on whether "the arrest and search are so separated in time or by intervening events that the latter cannot fairly be said to have been incident to the former." United States v. Abdul-Saboor, 85 F.3d 664, 668 (D.C. Cir. 1996). Thus, a search is incident to an arrest so long as it is "roughly contemporaneous with the arrest," which means that the search is "conducted within a 'reasonable time' after obtaining control of the vehicle," and occurs "during a continuous sequence of events." United States v. Hrasky, 453 F.3d 1099, 1101- 1102 (8th Cir. 2006) (upholding search conducted an hour after initial detention because the search was con temporaneous with decision to effect a full custodial ar rest) (citations omitted), cert. denied, 127 S. Ct. 2098 (2007); see United States v. Mapp, 476 F.3d 1012, 1019 (D.C. Cir.) (search occurring around ten minutes after arrest was sufficiently contemporaneous), cert. denied 127 S. Ct. 3031 (2007); United States v. Weaver, 433 F.3d 1104, 1106-1107 (9th Cir.) (upholding search initiated 10- 15 minutes after arrestee was placed in patrol car), cert denied, 547 U.S. 1142 (2006). That standard is amply satisfied here.
B. The Arizona Supreme Court's "Totality Of The Circum stances" Test Conflicts With This Court's Precedents
The Arizona Supreme Court incorrectly abandoned Belton's bright-line rule and replaced it with an ad hoc test that will require case-by-case adjudication. That analysis would interject substantial and undesirable uncertainty into a commonly recurring factual context confronted by officers in the field. The court held that a Belton search of a vehicle's passenger compartment is not authorized where, "based on the totality of the cir cumstances, an arrestee is secured" and thus, in a court's judgment, "presents no reasonable risk to officer safety or the preservation of evidence." J.A. 165-166. This case-by-case approach based on the "totality of the circumstances" cannot be squared with more than three decades of this Court's precedents, as well as the over whelming weight of lower-court authority, which make clear that Belton's applicability does not turn on whe ther the Chimel rationales were present in any particu lar case.
1. In Robinson, this Court held that a search inci dent to arrest of an arrestee's person is per se reason able and, accordingly, permissible under the Fourth Amendment, regardless whether the circumstances of the particular case involve one of the twin rationales for such a search as a general matter. 414 U.S. at 235. The Court rejected the contention that "there must be liti gated in each case the issue of whether or not there was present one of the reasons supporting the authority for a search of the person incident to a lawful arrest" and explained that such authority "does not depend on what a court may later decide was the probability in a particu lar arrest situation that weapons or evidence would in fact be found." Ibid.
Belton itself applied that principle to vehicle search es that are a contemporaneous incident of the lawful custodial arrest of a "recent occupant" of the vehicle. 453 U.S. at 459-460. In doing so, the Court rejected the proposition-advanced by the state court in Belton and the dissenters in that case-that "[w]hen the arrest has been consummated and the arrestee safely taken into custody, the justifications [for a warrantless search] cease to apply," because "at that point there is no possi bility that the arrestee could reach weapons or contra band." Id. at 465-466 (Brennan, J., dissenting); see id. at 456 (discussing state-court decision invalidating search because there was "no longer any danger" that arrestee could access article). As Justice Brennan spe cifically emphasized in his dissenting opinion, Belton's rationale squarely applies even after a recent occupant has been handcuffed and put in a patrol car. See id. at 468; see also United States v. Wesley, 293 F.3d 541, 548 (D.C. Cir. 2002).
Indeed, Belton illustrated the need for a "straight forward rule" by citing the different results previously reached in "comparable factual circumstances" by lower courts "decid[ing] whether * * * police may search in side the automobile after the arrestees are no longer in it." 453 U.S. at 459 & n.1 (citing, e.g., Hinkel v. Anchor age, 618 P.2d 1069, 1069-1070 (Alaska 1980), cert. de nied, 450 U.S. 1032 (1981), and Ulesky v. State, 379 So. 2d 121, 123 (Fla. Dist. Ct. App. 1979)). Both Hinkel and Ulesky involved situations in which the arrestee was in the back of the patrol car at the time that the vehicle was searched. The state court in Hinkel upheld the search of a purse retrieved from the vehicle as incident to the arrest. 618 P.2d at 1071-1072. The state court in Ulesky, by contrast, reasoned that, under the logic of Chimel, "once appellant was placed in the patrol car and thereby separated from her purse [in the vehicle], nei ther of the justifications for the search incident to arrest exception were present." 379 So. 2d at 126. While such reasoning would be consistent with a case-specific appli cation of Chimel's officer-safety and evidence-preserva tion rationales, it was precisely the uncertainty created by such case-by-case adjudication that Belton sought to displace by establishing a "workable rule" that would provide a "single familiar standard" in this critical and recurring context. Id. at 458, 460.
If there were any doubt about the bright-line nature of Belton's holding, this Court's decision in Thornton should have removed it. The petitioner in Thornton, who had been handcuffed and placed in a patrol car be fore his vehicle was searched, argued that the search was invalid in part because, on the particular facts of his case, he could not have readily accessed the passenger compartment of his car. 541 U.S. at 618, 622. In re sponse, the Court noted that the passenger compart ment and contraband in Belton itself were "no more in accessible" and that Belton was not based on a case-by- case assessment of the chance that an arrestee might retrieve a weapon from his car. Id. at 622-623. Rather, the Court explained, the danger, stress, and uncertainty arising from custodial arrests in general, and the need for a "clear rule" to guide police in that fluid situation, justify Belton's generalization that "it is reasonable to allow officers to ensure their safety and to preserve evi dence by searching the entire passenger compartment." Id. at 621, 623. As the Court explained, "[e]xperience has shown" that the "Chimel principle ha[s] prove[n] difficult to apply in specific cases" and that a rule based on "ad hoc determinations on the part of officers in the field and reviewing courts" was "impracticable" in this context. Id. at 620, 623.
Thus, far from leaving open the question, Belton and Thornton plainly reject the view that each vehicle search incident to arrest must be justified, under the totality of the circumstances of each case, with the dem onstrated presence of one of the Chimel rationales. Un surprisingly, then, the lower courts across the country have routinely and virtually unanimously applied Belton to situations in which the recent occupant of a car was arrested, handcuffed, and placed in a squad car before his vehicle was searched.1 The Arizona Supreme Court erred in reaching the contrary conclusion.
C. A Rule Requiring Proof Of A Threat To Officer Safety Or A Need To Preserve Evidence Under The "Totality Of The Circumstances" Of Each Case Would Obfuscate Belton's Bright-Line Rule
1. The Arizona Supreme Court's decision dissolves the bright-line rule adopted by Belton. It would create the same sort of uncertainty from the standpoint of the officer in the field and disarray in the case law that this Court specifically sought to remedy in Belton and Thornton. See also Wyoming v. Houghton, 526 U.S. 295, 305-306 (1999) ("When balancing the competing interests, our determinations of reasonableness under the Fourth Amendment must take account of * * * practical realities" such as the "bog of litigation * * * in the form of both civil lawsuits and motions to sup press in criminal trials" that would result from a rule that turns on post hoc inquiries into subjective beliefs of individuals or subtle factual distinctions.).
In Belton, the Court emphasized the need to provide police officers with a clear, easily administered rule for the dangerous and recurring situation involving the ar rest of the recent occupant of a vehicle, 453 U.S. at 458, acknowledging that "practical necessity requires that we allow an officer in these circumstances to secure thor oughly the automobile without requiring him in haste and under pressure to make close calculations about danger to himself or the vulnerability of evidence." Rob bins v. California, 453 U.S. 420, 431 (1981) (Powell, J., concurring in judgment). "A highly sophisticated set of rules, qualified by all sorts of ifs, ands, and buts and requiring the drawing of subtle nuances and hairline distinctions, may be the sort of heady stuff upon which the facile minds of lawyers and judges eagerly feed, but they may be 'literally impossible of application by the officer in the field.'" Belton, 453 U.S. at 458 (citation omitted).
The Arizona Supreme Court's decision reintroduces the very uncertainty and subtlety that Belton sought to foreclose. Under the court's decision, the determination whether Belton permits the search of an arrestee's car will require an individualized determination of whether, at the time of the search and "based on the totality of the circumstances," the arrest scene has been "secured" to the point that any threats to officer safety or evidence preservation are sufficiently remote that a search is not justified. J.A. 165-166. That inquiry revitalizes the case-by-case Chimel analysis that the Court found un workable in Belton. Returning to that regime would require law enforcement personnel to make a variety of ad hoc determinations-subject to second-guessing by a court-in the limited time that they have to assess the situation after arresting the recent occupant of a vehicle, Belton, 453 U.S. at 458, in the manner previously found "impracticable" by this Court. Thornton, 541 U.S. at 623.
The uncertainty of such an approach is highlighted by the Arizona Supreme Court's reliance on the "totality of the circumstances" in determining whether "an arres tee is secured." J.A. 165-166. That reliance implicitly recognizes that whether an arrestee is "secured" neces sarily is a question of degree. The series of steps that often follow custodial arrests can incrementally reduce the risk that an arrestee will free himself and either harm an officer or destroy evidence. Conducting an ini tial pat-down, applying handcuffs, performing a full search of the arrestee's person, separating the arrestee from others, placing the arrestee in a patrol car, and, ultimately, detaining the arrestee in a secure holding facility will each undoubtedly reduce such risk. At least in the relatively short period of time while officers re main at the scene of an arrest with the arrestee, how ever, there is no readily identifiable point at which a scene may reliably be said to be fully secure. Even when law enforcement officers have handcuffed an arrestee and placed him in a patrol car, arrestees occa sionally free themselves from their handcuffs, escape, and attempt to harm the officers.2
Under the decisions below, determining whether an arrestee is sufficiently "secured" may depend in part on the number of officers on the scene in relation to the number of arrestees, bystanders, or both. The Arizona Supreme Court distinguished this case from Belton on that basis, concluding that the lone officer faced "an ob vious threat to [his] safety" from the four vehicle occu pants in that case. J.A. 158. Of course, the number of officers, arrestees, and bystanders varies from case to case, and also may change during the arrest itself.
Other factors relevant to the "totality of the circum stances" approach affecting the analysis in any particu lar case would include whether the arrestees are placed in handcuffs or other constraints; whether their hands are cuffed behind or in front; the relative (and changing) locations of the officers, arrestees, bystanders, and the car; whether the arrestees are placed in patrol cars, where those cars are located, whether they are equipped with a prisoner cage, whether their doors or windows are open; and whether the officers monitor the cars dur ing the search. The inquiry would also depend on the size, strength, criminal history, and other characteris tics of the arrestees and bystanders, as well as whether the arrestees act nervous, agitated, compliant, or hostile or whether the arrestee poses a greater than average risk of escaping restraints (with large wrists and small hands). The time of day or night might also be relevant, along with the relative density of the area and danger ousness of the neighborhood. The possibility of a confed erate's late arrival would also have to be factored in. Officers would be required to make on-the-spot judg ments as to these and numerous other factors to deter mine whether the scene is sufficiently "secure" to pre clude a vehicle search. The need to monitor the chang ing dynamics of the arrest scene would eliminate the simplicity and predictability on which Belton predicated its bright-line rule and would mark a return to the un certain and hazardous world that existed for officers in the field before Belton. See 453 U.S. at 459.
2. The Arizona Supreme Court suggested that ap plying Belton's bright-line rule without a case-specific determination of whether the Chimel rationales were present would cut the search-incident-to-arrest doctrine adrift from its traditional "constitutional moorings" as set forth in Chimel. J.A. 163-164. Although this Court has found that most Fourth Amendment situations are not amenable to bright-line rules, see United States v. Drayton, 536 U.S. 194, 201 (2002), it has traditionally developed clear, per se rules in cases where such a rule would provide meaningful protection to officers in haz ardous situations without unduly infringing on citizens' privacy. For example, in Robinson, as discussed above, the Court announced a per se rule authorizing a search incident to arrest of the arrestee's person, regardless of whether the person posed any threat to the officer in a particular situation. See 414 U.S. at 235.
Similarly, in Pennsylvania v. Mimms, 434 U.S. 106 (1977) (per curiam), the Court held that police officers executing a traffic stop may order the driver to exit the vehicle, regardless of whether the officer has any rea son to suspect that the driver threatens his safety. See id. at 110-111. The Court explained that this per se rule was justified by the government's "legitimate and weighty" concerns for officer safety and the relatively slight intrusion on the driver's liberty or privacy. Ibid. Later, in Maryland v. Wilson, 519 U.S. 408 (1997), the Court extended Mimms to passengers of a stopped car. The Court rejected the respondent's contention that a bright-line rule was unwarranted because it would allow officers to detain passengers even when they posed no reasonable risk to officer safety, which was the only ra tionale justifying the seizure. Id. at 413 n.1. Instead, the Court concluded that the danger to officers arising from traffic stops in general justifies a per se rule allow ing the police to order passengers out of the vehicle, regardless of whether those passengers pose a reason able risk to the officers in the particular case. Id. at 413-414.
This Court has also adopted a bright-line rule autho rizing police, when executing a search warrant, to detain any occupants of the premises being searched, without requiring a case-by-case analysis of whether those occu pants pose a risk in each individual case. Michigan v. Summers, 452 U.S. 692 (1981). The Court again con cluded that the generally dangerous situation of execut ing a search warrant justifies the intrusion, even where there is no reason to believe that the bystanders threat en the officers' safety. See id. at 702-703 ("Although no special danger to the police is suggested by the evidence in this record, the execution of a warrant to search for narcotics is the kind of transaction that may give rise to sudden violence or frantic efforts to conceal or destroy evidence."). Accordingly, the Court concluded that "the risk of harm to both the police and the occupants is mini mized if the officers routinely exercise unquestioned command of the situation." Ibid.
All of these per se rules are overinclusive in the sense that they allow officers to take actions to protect themselves in situations that are potentially dangerous as a general matter, even though in many (if not most) particular instances, there may be no readily identifiable threat to officer safety. But the magnitude of the inter est being protected-officer safety-and the difficulty of isolating (before the fact) only true threats justifies a broader authority to search.
3. A bright-line rule is appropriate in the Belton context. As this Court has repeatedly held, custodial ar rests in general are dangerous and fluid situations giv ing rise to concerns for officer safety and preservation of evidence. See Robinson, 414 U.S. at 234 n.5; Thorn ton, 541 U.S. at 621. Indeed, much of the risk inherent to such arrests results from the uncertainty that an offi cer must confront in situations where the officer often may lack knowledge of factors increasing his risk of harm. Thus, while an officer must have probable cause to arrest an individual, the unknown characteristics of that individual and the surrounding environment war rant a bright-line rule that sufficiently protects officers in the field while executing custodial arrests.
The balance of constitutional interests strongly fa vors Belton's clear and workable rule for vehicle search es incident to arrest. As noted, officer safety, evidence preservation, and the practical need for an easily admin istrable rule in this frequently recurring factual context weigh heavily in favor of permitting vehicle searches contemporaneous to the arrest of a recent occupant of the vehicle.
Furthermore, an arrestee's expectation of privacy in his automobile's passenger compartment, while not in significant, is "limited." Robbins, 453 U.S. at 431 (Pow ell, J., concurring in judgment). Because automobiles necessarily travel through public thoroughfares in plain view, are pervasively regulated by states, "periodically undergo official inspection," and are "often taken into police custody in the interests of public safety," individu als have only a diminished expectation of privacy in a vehicle's passenger compartment. Chadwick, 433 U.S. at 12-13; see Houghton, 526 U.S. at 303. That privacy interest is "diminished further when the occupants are placed under custodial arrest." Robbins, 453 U.S. at 431 (Powell, J., concurring in judgment); cf. United States v. Edwards, 415 U.S. 800, 808-809 (1974) ("While the legal arrest of a person should not destroy the privacy of his premises, it does-for at least a reasonable time and to a reasonable extent-take his own privacy out of the realm of protection from police interest in weapons, means of escape, and evidence.") (citation omitted). In deed, an individual's expectation of privacy concerning the passenger compartment of a vehicle is reduced even further by the fact that, in many instances, the Fourth Amendment permits police to impound such vehicles and to inventory their contents. See Colorado v. Bertine, 479 U.S. 367, 371-372 (1987); South Dakota v. Opper man, 428 U.S. 364 (1976); Cooper v. California, 386 U.S. 58 (1967). Thus, as Justice Powell explained, "Belton trades marginal privacy of containers within the passen ger area of an automobile for protection of the officer and of destructible evidence" and the "balance of these interests strongly favors the Court's rule." Robbins, 453 U.S. at 431.
D. The Belton Doctrine Is Straightforward And Workable
1. The Arizona Supreme Court's abandonment of Belton's bright-line approach to vehicle searches was animated in part by its concern that the demonstrated presence of the Chimel rationales in each case was nec essary to provide needed limits to the Belton rule. See J.A. 158-159. That concern is unfounded because Belton has built-in limitations that have proven to be clear, workable, and sound in the mine run of cases.
First, Belton applies only when the arrestee is the vehicle's "recent occupant." 453 U.S. at 460; Thornton, 541 U.S. at 622. When the police confront and arrest the individual while he is in the car or right after he exits the car, it is clear that Belton applies. See Thornton, 541 U.S. at 623-624 ("So long as an arrestee is the sort of 'recent occupant' of a vehicle such as petitioner was here, officers may search that vehicle incident to the arrest."). Although, as the lower courts have recog nized, there comes a point at which the suspect can no longer be reasonably regarded as a "recent occupant" of the vehicle because of a significant lapse of time or dis tance from the arrestee's point of departure from his car, that difficulty does not arise in most searches inci dent to arrest where the arrest and search occur as part of a short and uninterrupted series of events.3 More over, time and distance-unlike relative security-are at least susceptible to objective measurement and there fore an administrable test.
Second, Belton requires that the search of the vehicle be undertaken as "a contemporaneous incident of th[e] arrest." 453 U.S. at 460. A search generally meets the contemporaneous-incident standard if it is an "integral part of a lawful custodial arrest process," such that the search and arrest are fairly regarded as "one continuous event." Abdul-Saboor, 85 F.3d at 668-669 (citation omit ted). Contrary to the suggestion of the Arizona Su preme Court (J.A. 158-159), the determination of whe ther a vehicle search is a "contemporaneous incident" to an arrest is straightforward and workable, and it sensi bly limits Belton searches to instances where the search is genuinely part of the arrest process. Accordingly, most courts have correctly concluded that Belton does not authorize the search of a vehicle if the arrestee or his vehicle has been removed from the scene before the search is conducted, or if the search has not been con ducted within a reasonable time of the arrest. See, e.g., United States v. Wells, 347 F.3d 280, 287 (8th Cir. 2003), cert. denied 541 U.S. 1081 (2004); United States v. Lugo, 978 F.2d 631, 634-635 (10th Cir. 1992); Hrasky, 453 F.3d at 1102-1103.
2. In an opinion concurring in the judgment in Thornton, Justice Scalia proposed an additional limiting principle to govern the Belton rule. See 541 U.S. at 625- 632. Believing that the typical Belton search occurs only after the suspect is secure, id. at 625-629, Justice Scalia suggested narrowing Belton to vehicle searches con ducted when it is "reasonable to believe evidence rele vant to the crime of arrest might be found in the vehi cle." Id. at 632.
That alternative rule is unwarranted. If there are reasonable grounds to believe that a vehicle contains evidence of a crime, a warrantless search of that car would be based on probable cause, see Houghton, 526 U.S. at 302; Ornelas v. United States, 517 U.S. 690 (1996), and, thus, would be lawful under the automobile exception to the warrant requirement. See Maryland v. Dyson, 527 U.S. 465, 466-467 (1999) (per curiam); Houghton, 526 U.S. at 300-301. The proposed restric tion on Belton, thus, is effectively subsumed within dis tinct Fourth Amendment doctrines. As such, it would serve no independent purpose and would risk substan tial doctrinal confusion among the lower courts.4
Moreover, recasting Belton as based upon police in terest in gathering evidence related to the crime of ar rest would create irreconcilable tension with the logic of Belton's current limitations. If the reasonable belief that evidence will be found, combined with the arrestee's diminished expectation of privacy in the automobile con text, justifies a warrantless search of the car, it is not clear why the doctrine should be limited to situations where the arrestee was a recent occupant of the vehicle and the search was contemporaneous with the arrest. The new rationale would also seem to justify a search of the trunk, as well as the passenger compartment and containers within. Nor is it clear why the limitation to evidence of the crime of the arrest makes any sense. Unless one entirely accepts that no appreciable risk of destruction of evidence exists in a typical Belton search, cf. 541 U.S. at 625-629 (Scalia, J., concurring in the judg ment), the temptation to destroy evidence presumably will be just as great in the case of evidence of a crime more serious than the crime of arrest. Thus, transform ing Belton along the lines suggested would create confu sion both in actual practice and in the underlying logic of Belton searches.
Finally, recharacterizing Belton in the manner sug gested by Justice Scalia's Thornton concurrence cannot be squared with the rationale of Belton itself. Justice Stevens concurred in the judgment in Belton because he would have held that the "automobile exception" to the warrant requirement authorized the search because the officers had "probable cause to believe the vehicle con tained contraband." Robbins, 453 U.S. at 444, 449-452 & n.13 (Stevens, J., dissenting); see Belton, 453 U.S. at 463 (Stevens, J., concurring in the judgment) (adopting rationale in Robbins dissent). But the State in Belton never argued that the vehicle search was lawful on that ground, Robbins, 453 U.S. at 452 n.15 (Stevens, J., dis senting), and Belton made clear that its holding did not rest on the automobile exception, which "proceeds on a theory wholly different from that justifying [a] search incident to an arrest" and is "not dependent on the right to arrest," Chambers v. Maroney, 399 U.S. 42, 49 (1970) (quoting Carroll v. United States, 267 U.S. 132, 158 (1925)). See Belton, 453 U.S. at 462 n.6 (citing Cham bers); see also id. at 463 (Rehnquist, J., concurring) (concurring "because the Court does not find it neces sary to consider the 'automobile exception' in its disposi tion"); id. at 472 (White, J., dissenting) (Belton autho rizes searches without "probable cause to believe that contraband or evidence of crime will be found"). Rather than recast Belton as a rule about evidence-seeking searches, the Court should reaffirm that Belton rests on the traditional justifications of the search-incident-to- arrest doctrine-officer safety and evidence preserva tion-in the recurring context of vehicle searches follow ing the arrest of a recent occupant.
The judgment of the Supreme Court of Arizona should be reversed.
PAUL D. CLEMENT
ALICE S. FISHER
Assistant Attorney General
MICHAEL R. DREEBEN
Deputy Solicitor General
ANTHONY A. YANG
Assistant to the Solicitor
JOSEPH F. PALMER
1 See, e.g., Mapp, 476 F.3d at 1015, 1017-1019; Wesley, 293 F.3d at 545-549 & n.8 (citing cases); United States v. Doward, 41 F.3d 789, 791 & n.1 (1st Cir. 1994) (citing cases), cert. denied, 514 U.S. 1074 (1995); United States v. Milton, 52 F.3d 78, 80 (4th Cir.), cert. denied, 516 U.S. 884 (1995); United States v. White, 871 F.2d 41, 44 (6th Cir. 1989); United States v. Sholola, 124 F.3d 803, 817-818 & n.15 (7th Cir. 1997) (citing cases); United States v. Mitchell, 82 F.3d 146, 152 (7th Cir.), cert. denied, 519 U.S. 856 (1996); United States v. Karlin, 852 F.2d 968, 970-971 (7th Cir. 1988), cert. denied, 489 U.S. 1021 (1989); Hrasky, 453 F.3d at 1100, 1103; Conrod v. Davis, 120 F.3d 92, 94 (8th Cir. 1997), cert. denied, 523 U.S. 1081 (1998); Weaver, 433 F.3d at 1107; United States v. Osife, 398 F.3d 1143, 1144, 1146 (9th Cir.), cert. denied, 546 U.S. 934 (2005); United States v. Humphrey, 208 F.3d 1190, 1202 (10th Cir. 2000); Rainey v. Commonwealth, 197 S.W.3d 89, 91, 95 (Ky. 2006), cert. denied, 127 S. Ct. 1005 (2007); People v. Daverin, 967 P.2d 629, 631-632 (Colo. 1998); People v. Bailey, 639 N.E.2d 1278, 1281-1282 (Ill. 1994), cert. denied, 513 U.S. 1157 (1995); State v. Hensel, 417 N.W.2d 849, 852-853 (N.D. 1988); State v. Stroud, 720 P.2d 436, 437-438 (Wash. 1986); State v. Fry, 388 N.W.2d 565, 567, 577 (Wis.), cert. denied, 479 U.S. 989 (1986); see also 3 Wayne R. LaFave, Search and Seizure § 7.1(c) at 517 & n.89 (4th ed. 2004) ("[U]nder Belton a search of the vehicle is allowed * * * even after the defendant was removed from it, handcuffed, and placed in the squad car.") (citing cases).
2 See, e.g., Mason v. United States, 120 Fed. Appx. 40 (9th Cir. 2005) (suspect handcuffed and locked in back of car kicked out window, es caped, freed hands, and grabbed agent's gun); Smith v. Cupp, 430 F.3d 766 (6th Cir. 2005) (suspect handcuffed in back of car climbed over seat to front, put car in gear, and attempted to run over officer); Plakas v. Drinski, 19 F.3d 1143, 1145 (7th Cir.) (suspect handcuffed in backseat of squad car escaped from squad car and later confronted police), cert. denied, 513 U.S. 820 (1994); United States v. Sanders, 994 F.2d 200, 210 & n.60 (5th Cir.) (citing incidents in which police officers were slain by handcuffed arrestees), cert. denied, 510 U.S. 955 (1993); see also Amer icans for Effective Law Enforcement Amicus Br. at 11-12 (citing cases); Doward, 41 F.3d at 793 n.5 (discussing "the unpredictable develop ments ultimately confronting" police in Belton context, including the possibility that bystanders or unknown confederates in the area may approach the vehicle); id. at 791-793 & n.1; Forge v. City of Dallas, No. 3-03-CV-0256-D, 2003 WL 21149437, at *1 (N.D. Tex. May 19, 2003) (arrestee who was handcuffed and secured with a seatbelt in a locked patrol car "suddenly and without warning * * * slipped out of his handcuffs, released the seat belt latch, opened the locked car door, and tried to escape from custody").
3 See, e.g., United States v. Strahan, 984 F.2d 155, 159 (6th Cir. 1993) (Belton does not apply where arrestee was "approximately thirty feet from his vehicle when arrested"); Dean, 76 P.3d at 437 (arrestee was not "recent occupant" under Belton where "[h]e had not occupied the vehicle for some two and one-half hours," and was found hiding in the attic of a nearby house); State v. Porter, 6 P.3d 1245, 1249 (Wash. Ct. App. 2000) (Belton does not apply where individual was arrested 300 feet from vehicle).
4 The "reasonable to believe" formulation suggested by Justice Scalia presumably refers to probable cause and not a novel standard between probable cause and reasonable suspicion. This Court has properly rejected the invitation to create such a "third verbal standard" because creating new and "subtle verbal graduations may obscure rather than elucidate the meaning" of the "constitutional requirement of reasonable ness." United States v. Montoya de Hernandez, 473 U.S. 531, 541 (1985).