RESPONSE BY: FBI SUPERVISORY SPECIAL AGENT DAVID WILLIAMS
DAVID R. WILLIAMS RESPONSE TO OIG FINDINGS RELATED TO THE ABILITY OF SSA WILLIAMS TO ACCURATELY PREDICT THE VELOCITY OF DETONATION OF AN UNKNOWN QUANTITY OF EXPLOSIVE AND THEN TO ACCURATELY PREDICT THE AMOUNT OF THAT EXPLOSIVE.
ESTIMATE OF VELOCITY OF DETONATION (VOD)
ESTIMATE OF WEIGHT OF THE EXPLOSIVE MAIN CHARGE
1. The need and requirements for an initial on scene rough estimate must be defined so that investigators may have a logical starting point. It has been an accepted policy of the FBI Laboratory Explosives Unit to make an approximation of what type of explosive could have caused the explosive damage viewed at a bombing crime scene. The purpose of an on-site estimate/approximation is to assist the investigators by providing them with a gross effects analysis regarding quantity and type of explosives used in the crime.
For more information regarding views of the initial on-site investigator and an initial assessment, see: Explosion Investigation and analysis, Kennedv on Explosives, Kennedy, Patrick M, John Kennedy, Investigations Institute, Chicago, Ill., 1990.
2. I have also had the personal experience of viewing known quantities of known commercial explosives with documented velocities of detonation, predicted by the manufacture, at less than 500 feet per second intervals. I have witnessed hundreds of these explosives on many assorted target materials, such as steel, vehicles, wood, concrete, cloth and other materials. I have through these experiences, gained the knowledge of what types of explosives could cause different explosive damage to different types of materials at varying distances.
3. "Following the detonation of a terrorist bomb one important forensic and investigative task is to determine the nature and the approximate size of the explosive charge employed. The general nature of the explosive can be identified from the physical evidence such as the degree of shattering close to the seat of the explosion." This quote may be located in the enclosed DERA report, PSLD/CES/FEL/CR9636 on page 1. This report also includes the results of visual and physical inspections of known quantities of improvised explosive mixtures, specifically 5,000 pounds of ANFO, 1,000 pounds of TNT, 1,000 and 5,000 pounds of ammonium nitrate and sugar mixtures (AN/S). I had the opportunity to be a part of testing and research involving AN/S and urea nitrate in 1994, prior to the explosion at the Alfred Murrah Federal Building in Oklahoma City, April 19, 1995.
4. To my knowledge, incident-specific empirical data was not available at the time of the Murrah Building bombing, with the exception of the CONWEP computer program, research and data acquisition gathered from the Dipole Mite (ATF) project, tests conducted during a joint project with the British DERA and the FBI at Socorro, NM., data gathering and the preparation of a book written by Mr. Paul Cooper entitled, Explosives Engineering, 1996. This book was in the research stage for a number of years prior to the Oklahoma bombing and I had spoken to Mr. Cooper and listened to his lectures regarding the predictability of explosives and explosive damage prior to the bombing.
5. A point taken by many of the explosives experts regarding the estimation of what type of explosive and the weight estimate of the explosive main charge is to observe damage, cratering, and all other physical indications, and work back to a rough charge weight and general type.
6. As an alternative to making an estimation of weight and type of explosive, and would be totally accurate, safe, and completely worthless input at a crime scene, would be to say, "the amount and type of explosives are unknown", "the velocity of detonation is between 3,000 and 30,000 feet per second" or "the weight of the explosive main charge is approximately 10 to 10,000 pounds."
7. Formal education or a doctorate in chemistry provides little basis for the analysis of explosives effects. A possible exception, if the thesis is so selected, degrees from mining/blasting locales or universities, such as the New Mexico Mining and Technical Institute.
8. One must also take into consideration, post crime scene analysis of the debris and componentry in the Laboratory. After the evidence is collected and submitted to the Laboratory, additional analysis of the debris is conducted to more completely verify the on-scene estimate. Should any indication of that initial estimate be disproved or modified, the Laboratory report would reflect that opinion.
9. Bombings such as have been experienced and directed at this country such as the World Trade Center, Oklahoma City, Pan Am 103, Beirut and others, by their nature, are considered a matter of public safety or extreme emergency for fear of other devices and linkage to other bombings. In nearly all cases, no chemistry examinations or laboratory findings are available initially, and in some cases never are known. It is therefore necessary to provide a timely estimate upon reasonable and prudent technical data and observational data used within the explosives community which may include:
-apparent crater/actual dimensions
-crater lip geometry
-possible bomb debris
-gross explosive residues including soot, especially at blast diffraction zones
-fragment and hot particle impact on structures and objects
-injuries to people
-window and lightweight structure damage
-all possible device components
-eyewitness reports of preblast conditions such as fireball, odor sound, etc.
The above list is a brief summary. For a comprehensive list of additional factors concerning observational data that could be collected see the attached bibliography.
10. Information compiled from physical observations contribute to a sound basis for a reasonable and useful judgment and reconciliation as to the type of explosive after which a velocity of detonation can be estimated.
11. In both the World Trade Center and in the Oklahoma City bombings, the following observations were noted:
The condition of near field debris indicative that C-4 or Semtex like plastic explosives was not used:
-absence of deep cratering, severe spalling, and small fragments and items that are characteristic of a highly brisant explosive.
-the general appearance of a long push on the immediate structures.
-glass breakage function of quantity and distance.
-absence of a carbon soot at blast diffraction zones, dark soot being indicative of fuel-rich explosives such as C-4.
-absence of carbon soot indicative of either oxygen rich or stoichiometrically balanced fuel/oxygen explosives such as EGDN/NG based dynamites and ANFO.
12. The destructive power of an explosive is based upon:
characteristic detonation velocity and pressure, confinement, tamping, method of initiation, impulse profile, and brisance value, site parameters such as stand-off from witness surfaces.
13. Ammonium nitrate and fuel oil (ANFO) has a broad spectrum of Velocities of Detonation according to numerous references. However, some of these references are more specific when establishing parameters.
-a military catering charge lists a VOD of 10,700 feet per second (fps).
-a 4" diameter steel tube confinement is at 10,000 fps
-a 16" diameter tube is at 16,000 fps
-when ANFO is used in boreholeing, the VOD has a positive slope as a function of depth, the VOD increases as the detonation front progresses down the borehole.
-enhanced effects of very large quantities, which is essentially self tamping, the VOD is expected to be in the 13,000-15,000 fps range.
-a ballpark approximation for very large quantities of blasting agents, which is accepted in the commercial industry, is roughly half the VOD of C-4/plastics, which equates to 13,000 fps.
14. During the crime scene evaluation in Oklahoma City, and during the Laboratory analysis of the debris collected, it was obvious that neither a 4" nor a 16" steel tube was used to create the physical observable damage. It was also obvious by the crime scene damage that the explosive main charge was not placed in a borehole. The logical conclusion is that there was a large quantity of explosive, and if it was ANFO it would have fallen into the parameters of a self tamping explosive having a VOD of approximately 13,000 fps. A cursory evaluation of the VOD approximation of 13,000 fps can seem that the value was too high, however, a reasonable examination of the data indicates that the VOD estimation is well within a logica1 bracket based upon physical indications and accepted professional publications, especially considering the large amount used.
15. No single VOD exists for a non-ideal explosive, such as ANFO, a complete answer must address charge size, diameter and confinement. There is a lack of data, except for borehole applications, especially for large improvised explosive devices.
16. Any precise VOD experimental results would require reference to and the limits of those test conditions only. A precise value serves no greater value when considering all the other variables and uncertainties. It is important to note that the significance of an accurate and precise VOD is very limited. It should also be noted that although the VOD of ANFO has a variance of nearly 8,000 fps, due to the factors affecting the VOD and the lack of non-consumed excessive blasting agent, soot deposits and near-target damage, the VOD's for ANFO in the lower areas was not worthy of mention. The approximation of a VOD
between approximately 12,000 fps and 14,000 fps is a reasonable and logical evaluation considering all of the physical and observable characteristics of the crime scene.
17. Early crime scene estimates are necessary to offer investigators a basis for investigative action. Certainly, long after Laboratory analysis and technical facts are known, critics and experts can and did surface, and indicated such statements as, "I would have analyzed the crime scene this way...". Monday morning quarterbacking does not get the immediate investigation underway. After detailed examination of the specimens submitted to the Laboratory, I conducted an analysis not in an attempt to prove my original estimation of VOD and weight of the main charge, but to disprove that theory. I focus on this aspect in every case that I examine. During the course of my examination, I found no conflicting data that would have or did change my original estimate. Should I have found conflicting data arguing that the VOD was not approximately 13,000 fps and the weight of the explosive main charge was not approximately 4,000 pounds, I would have incorporated the correct estimate in my report, indicating that the initial assessment was in error.
WORLD TRADE CENTER BOMBING
ESTIMATE OF VELOCITY AND WEIGHT OF MAIN CHARGE
18. During my original estimate of the VOD and weight charge of the explosive at the World Trade Center (WTC), I was more cautious due to the environment at the crime scene.. The lED, as was apparent, was inside of an enclosed building. Much of the physical blast damage examined and used for an estimate, was material that was in the near-field blast damaged area. The explosive used, displayed characteristics unique to an "indoor arena" and many of the other physical damage was not available, such as: window breakage at great distances, overturned vehicles, no parking signs on posts, light and heavy structures that would have been affected by blast pressure at varying open air distances, etc. I do agree that there has been no published data on very large explosive devices functioning inside buildings, however, there is much documentation and modeling of small explosives functioning inside of a building.
19. Prior to the initial examination of the WTC crime scene, I had witnessed hundreds of explosives varying in VODs from 3,000 to 26,000 fps directed at an array of assorted target materials, such as steel, concrete and automobiles. Granted, the amount of explosive was never more than 100 pounds, however, the normal characteristic damage of known explosives on known target materials may be extrapolated. Due to the indoor arena and the fact that such a large explosive main charge was used, larger than 100 pounds, I feel that I am well within my boundaries to estimate the VOD in a bracketed parameter of approximately 14,000
fps with a bracket of 2,000 fps on either side, thereby making the VOD approximately 12,000 to 16,000 fps. This is reasonable and prudent estimate of the VOD.
20. At the time of testimony at the WTC trial, I had already witnessed the detonation of approximately 1 pound of TNT on a steel plate and approximately 1 pound of the urea nitrate, that was made in Eglin, detonated on a steel plate. Both test detonations used an exploding bridge wire. Assuming that the ideal VOD for TNT is approximately 20,000 to 22,000 fps, and is considered the lower end of the "brisant" explosives, I was able to witness unique, predictable explosive damage to the steel plate target material. The explosive damage caused to a similar steel plate during the explosive testing of urea nitrate was also unique, however at this time, not predictable. The explosive damage caused by the urea nitrate was approximately 2/3 of the mid range estimate of TNT (21,000 x 2/3 = 14,000) and displayed a longer impulse type damage. Pushing or long duration impulse is defined as a longer duration of terminal blast pressure as compared to the detonation pressure and duration of an ideal explosive, TNT. This was the first time I was able to truly "test" the theory that I had arrived at on my initial damage assessment at the WTC crime scene. This test confirmed that the VOD of the explosive was well within a reasonable and prudent parameter of my initial estimate. The explosive damage at the WTC displayed a long duration high pressure curve with none, or very, very little "brisant" explosive damage. Interior concrete block walls displayed the same type of long pressure wave duration. I would not expect to see that type of damage from a more brisant explosive or from an explosive having a VOD of much less than 13,000 fps.
21. To reiterate, although I had not, at the time of the WTC crime scene, witnessed first hand, such a large explosive device, I had viewed detailed photographs, conversed with crime scene personnel, and reviewed reports concerning the three Beirut bombings and several of the large IRA IEDs. Knowing the results of the chemical analysis and the opinions of the investigators involved in these bombing., I was able to compare this type of damage to the damage I viewed in the WTC. Several of the crime scene personnel and Laboratory examiners who had worked on the Beirut and IRA bombings concurred with me.
22. As far as the chemical analysis of the residues from the WTC, it has been the experience of many laboratories that explosive residues are not commonly recovered following the explosion of a fertilizer based lED, such as urea nitrate and ANFO, of this magnitude and non-ideal type of explosive. One must also consider that the British and Irish Laboratories have had very little success in identifying explosive residues from ammonium nitrate based bombs, but in fact many opinions are
available from them concerning a size/weight estimate of the AN/S IRA devices.
In addition, a double blind testing area occurred in the TWA 800 incident. This matter is one that could never have been duplicated and was in the worst possible scenario. The crime scene was underwater, under sea water. And prior to any knowledge of explosives on-board, the FBI laboratory found, and had confirmed by DERA, explosive residue consistent with C-4 on a piece of carpet. This was found prior to any knowledge by the FAA or NTSB that a dog training program had occurred on that aircraft in the exact location that the dog handlers had said they had placed the explosive, C-4.
23. During the course of your additional investigation concerning my veracity, your department should interview Mr. James A. Petrousky, Office of Special Technology, 10530 Riverview Road, Fort Washington, Maryland 20744, telephone (301) 292-8525. Mr. Petrosky has a degree in chemical Engineering, has 22 years in EOD research and development at the Naval EOD Technology Center in Indian Head, Md., has published works on pre-blast and render safe techniques, several patents, is well known as an explosive expert by his peers around the world, including members of your panel. Mr. Petrousky will be able to shed some light on the ability of an experienced bombing crime scene investigator to accurately predict the VOD and weight of an explosive by an examination of the crime scene and the debris collected due to his observations following the explosions relative to his testing and research.
Your office should also interview Mr. Calvin Walbert, FAA security, who has also witnessed many explosives and will be able to speak coherently about my veracity.
Mr. Paul W. Cooper, who is also known to your panel, has been working on a book for the past several years. This book is now in print, "Explosives Engineers". Prior to my testimony at the WTC trial, I had spoken to Mr. Cooper on several occasions concerning blast damage and VOD. In Mr. Cooper's book he provides "empirical data" suggesting that a VOD may be estimated to within a dedicated bracket (refer to his book in the chapter entitled, "Predicting Velocity of Detonation"). I would recommend a conversation with Mr. Cooper. Please refer to his "Rule of Thumb" as published.
The U.S. Army Corps of Engineers and Engineering Waterways, Vicksburg, Mississippi was present at both the WTC and Oklahoma City bombings, and prepared a report concerning their findings on both bombings. Their results were incredibly similar to my findings. Waterways is a research agency who is also deeply involved in the DIPOLE MITE research project. I have read
the reports of findings on the DIPOLE MITE project prior to Oklahoma City.
In both the WTC bombing and the Oklahoma City bombing, .1 utilized the CONWEP system (advanced computer program for blast effects). At the time, this was one of the only available computer program available. Currently, due primarily to the upsurge in large fertilizer based bombings, the U.S. government is funding evaluation studies in this area with emphasis on fertilizer grade ammonium nitrate. If the WTC and Oklahoma City bombings were not ANFO or urea nitrate, the US government is wasting a lot of money.
Also enclosed herewith is a publication generated by the Canadian Bomb Data Center, which describes Fragment Analysis, in a size ratio with a faster, more brisant explosive causing "smaller" fragments, as compared to slower explosives.
24. The following is a bibliography of selected open publications on explosive effects. I was familiar with many of these publications and/or excerpts from these publications, prior to the bombing of the WTC.
-Kolsky, H., Stress Waves in Solids, Applied Physics Brown Dover Publications, Inc., New York, 1963.
-Reinhart, John S., Stress Transients in Solids, Department of Mechanical Engineering University of Colorado, Hyperdynamics, Santa Fe, New Mexico, 1975.
-Johnson, W., Impact Strength of Materials, University of Manchester Institute of Science and Technology, Edward Arnold, Ltd., 1972.
-Chou, Pei Chi, and Alan K. Hopkins, Dynamics Response of Materials to Intense Impulsive Loading, Drexel University, Philadelphia, Pa., and Air Force Materials Laboratory, Wright Patterson AFB, Ohio, 1972.
-Zukas, Jonas A., Theodore Nichols, Hallock F. Swift, Longin B. Greszczuk, and Donald R. Curran, Impact Dynamics, John Wiley and Sons Publishing USA, 1972.
-Kornhauser, M., Structural Effects of Impact, Spartan Books, Inc., Baltimore, Md., Cleaver-Hume Press, London, 1964.
-Billington, E.W., and A. Tate, The Physics of Deformation and Flow, Royal Armament Research andDevelopment Establishment, Fort Halstead, U.K., McGraw-Hill International Book Company, 1981.
-High Velocity Deformation of Solids, Kozo Kawata and Jumpier Shioiri editors, Iutam Symposium Tokyo, Japan, August 24-27, 1977, Springer-Verlag Publishers, 1977.
-Baker, Winf ield, Explosives in Air, Wilfred Baker Engineering, San Antonio, Published in cooperation with the Southwest Research Institute, 1983.
-Bartknecht, W., Explosions Course Prevention Protection, Translation from the German by Brug and T. Almond, Springer-Verlag, 1981.
-Chigier, N.A., Progress in Energy and Combustion Science, Volume 6, Pergamon Press, 1981.
-Noon, Randall, Engineering Analysis of Fires and Explosions, CRC Press, 1995..
-Field, Peter, Dust Explosions, Handbook of Powder Technology, Volume 4, Elsevier Scientific Publishing Company, 1982.
-Bulson, P.S., Structures Under Shock and Impact, Proceedings of the first International Conference, Cambridge, Mass., 1989.
-Structural Design for Hazardous Loads, The Role of Physical Testing, edited by, J.L. Clarke, F.K. Garas and G.S.T. Armer, Brighton, Uk, April 17-19, 1991.
-Bangash, M. Y. H., Impact and Explosion, Analysis and Design, CRC Press, , 1993.
-Henrych, Josef, The Dynamics of Explosions and Its Use, Developments in Civil Engineering., 1, Elsevier Scientific Publishing Company, 1979.
-Han, Zhaoyuan and Xiezhen Yin, Shock Dynamics, Kluwer Academic Publishers/ Science Press, 1993.
-Baker, W.E. P.A. Cox, P.S. Westine, J.J. Kulesz and R.A. Streshlow, Explosion Hazards and Evaluation, Elsevier Scientific Publishing Company, New York, 1983.
-Kohler, Josef and Rudolf Meyer, Explosives, Forth Revised and extended edition, VCR Weinheim, FRG), 1993.
-Cooper, Paul W., and Stanley R. Kurowski, Introduction to the Technology of Explosives, VCH Publishes, 1996.
25. According to the OIG findings, the OIG states that no empirical data available on the subject of VOD estimates and estimates of weight charges of an lED. I strongly disagree based upon the above mentioned references and experts in the field
26. I will concede that the conclusionary portion of my September 5, 1995 Laboratory report regarding Oklahoma City, is categorically overstated. One must consider two facts, first, my laboratory report is a compilation of comparison examinations concerning items found at the bombing crime scene and items recovered during auxiliary searches. This comparison examination is a request from the field offices to determine what, if any type of explosive device, could have been constructed from components recovered at the auxiliary searches and how these components could be associated with the bombing crime scene lED. I should have included a para graph in my report stating that request was being addressed in that report. Secondly, all of the Laboratory reports that I prepare are required to undergo a technical and administrative review. It is apparent that the individual(s) who had reviewed my report were either in agreement with me or were not technically qualified to conduct the review and the report should have been amended.