Skip to main content
Press Release

MS-13 Gang Member Sentenced to 25 Years’ Imprisonment for Murder on Long Island

For Immediate Release
U.S. Attorney's Office, Eastern District of New York
Gang Members Attacked Victim with Machetes and a Baseball Bat on a Residential Street

Earlier today, at the federal courthouse in Central Islip, Marlon Guevara, also known as “Mosquito,” a member of the Sailors Locos Salvatruchas Westside clique of La Mara Salvatrucha, also known as the MS-13 (MS-13), a transnational criminal organization, was sentenced by United States Circuit Judge Joseph F. Bianco to 25 years’ imprisonment for his participation in the October 13, 2016 murder of Dewann Stacks, and conspiracy to distribute marijuana.  Guevara pleaded guilty to the charges in January 2019.  Upon completion of his sentence, Guevara faces deportation from the United States.

Richard P. Donoghue, United States Attorney for the Eastern District of New York, William F. Sweeney, Jr., Assistant Director-in-Charge, Federal Bureau of Investigation, New York Field Office (FBI), Geraldine Hart, Commissioner, Suffolk County Police Department (SCPD), and Patrick J. Ryder, Commissioner, Nassau County Police Department (NCPD), announced the sentence.

“With today’s sentence, Guevara will now pay for participating in the execution of Dewann Stacks as part of MS-13’s warped mission to attack and kill perceived rivals,” stated United States Attorney Donoghue.  “The brutality of this murder is a reminder of the necessity of the Eastern District’s and the FBI’s Long Island Gang Task Force’s commitment to eradicate the MS-13.”

“While today’s sentence might not salve the pain this man inflicted on Mr. Stack’s family, and the community terrorized by the violence going on around them, it does send a message to others they will be held accountable for their murderous and criminal actions,” stated FBI Assistant Director-in-Charge Sweeney.  “Our FBI Long Island Gang Task Force is doing all we can to stop MS-13 from further harming anyone, and we’ve made a truly significant impact.  Having said that, we still need the community members to know they can come forward with information so we can continue the progress.”

“The senseless homicide of Dewann Stacks, who was brutally attacked in an incomprehensible manner, is a reminder of the ruthlessness and violence committed at the hands of MS-13,” stated SCPD Commissioner Hart.  “Our commitment to dismantling MS-13 has led to today’s sentencing, and I would like to thank the Eastern District of New York and the FBI’s Long Island Gang Task Force for their dedication to holding these gang members accountable for their heinous crimes.” 

“Today’s sentencing in the brutal murder of Dewann Stacks by MS-13 gang member Marlon Guevara shows that law enforcement is working together with our state and federal partners.  We will expand every resource to arrest those offenders of these horrific crimes and follow through until conviction and sentencing.  Our combined zero tolerance approach will continue to keep our residents and communities safe,” stated NCPD Commissioner Ryder. 

According to court filings and facts presented during the sentencing proceeding, on October 13, 2016, Guevara and other MS-13 co-conspirators drove around the streets of Central Islip and Brentwood hunting for rival gang members to attack and kill.  They spotted Stacks on American Boulevard in Brentwood and, believing him to be a rival gang member, decided to kill him.  Guevara, wielding a machete, and two other MS-13 members, one armed with a machete and the other a baseball bat, attacked Stacks, beating and hacking him to death.  The victim sustained severe sharp and blunt force trauma to the face and head, rendering him nearly unrecognizable.    

From April 2016 to March 2017, Guevara and members and associates of the Sailors clique sold street-level quantities of marijuana in and around Brentwood.  The profits were turned over to the clique leaders, who purchased more marijuana and firearms and wired money to MS-13 leaders in El Salvador

Guevara was 17 years of age at the time of the murder, and was initially charged by a juvenile information.  He subsequently agreed to be transferred to adult status for trial and, in January 2019, he waived indictment and pleaded guilty.

Today’s sentencing is the latest in a series of federal prosecutions by the United States Attorney’s Office for the Eastern District of New York targeting members of the MS-13.  The MS-13’s leadership is based in El Salvador and Honduras, but the gang has thousands of members across the United States, and they are primarily immigrants from Central America.  With numerous branches, or “cliques,” the MS-13 is the largest and most violent street gang on Long Island.  Since 2003, hundreds of MS-13 members, including dozens of clique leaders, have been convicted on federal felony charges in the Eastern District of New York.  A majority of those MS-13 members have been convicted on federal racketeering charges for participating in murders, attempted murders and assaults.  Since 2010, this Office has obtained indictments charging MS-13 members with carrying out more than 50 murders in the Eastern District of New York, and has convicted dozens of MS-13 leaders and members in connection with those murders.  These prosecutions are the product of investigations led by the FBI’s Long Island Gang Task Force, comprising agents and officers of the FBI, SCPD, NCPD, Nassau County Sheriff’s Department, Suffolk County Probation, Suffolk County Sheriff’s Department, Rockville Centre Police Department, New York State Police and Bureau of Alcohol, Tobacco, Firearms and Explosives. 

The government’s case is being handled by the Office’s Long Island Criminal Division.  Assistant United States Attorneys John J. Durham, Paul G. Scotti and Justina L. Geraci are in charge of the prosecution.

The Defendant:

MARLON GUEVARA (also known as “Mosquito”)
Age: 20
Brentwood, NEW YORK

E.D.N.Y. Docket No. 18-CR-275 (S-1) (JFB)


John Marzulli
United States Attorney’s Office
(718) 254-6323

Updated October 10, 2019

Drug Trafficking
Project Safe Neighborhoods
Violent Crime