On March 3, 2010, Umaña pled guilty to  aiding and abetting the use of a firearm during a crime of violence  resulting in the death of the pimp, Claros Luna, through the use of a  handgun.  According to court records, in July 2009, Luna transported  women from Maryland to Virginia to engage in prostitution.  Posing as  potential customers, Umaña and two other MS-13 gang members—Adolfo Amaya  Portillo and Eris Arguera—lured Claros Luna and the prostitute to Manor  Road in Alexandria, Va., on July 29, 2009.
Once Luna and the prostitute arrived at  Manor Road, the prostitute exited the vehicle and entered the apartment  building at 704 Manor Road.  Arguera, brandishing a handgun, met the  prostitute in the lobby and directed her to the nearby vehicle where  Luna sat waiting in the driver's seat.
Arguera and the prostitute  entered the rear driver's side door of the vehicle.  Portillo, armed  with a handgun, entered the front passenger door.   Umaña, armed with a  knife, entered the rear passenger-side door of the vehicle.  Portillo  demanded rent or extortion payments from Luna.  Luna attempted to grab  Portillo's handgun. Umaña then put his knife to Luna's throat.
Portillo and Arguera fatally shot Luna three times.  Portillo fired two  of the three fatal shots—one to Luna's chest and a second contact  wound to Luna's head.  A third shot entered the left side of Luna's back  and exited his chest.  Portillo, Arguera, and Umaña then took the money  that Luna and the prostitute had earned from the prostitution business  that day.
This case was investigated by the Alexandria  Police Department and FBI's Washington field office, with assistance  from the Fairfax County and Arlington County Police Departments and U.S.  Immigration and Customs Enforcement's Office of Investigations in  Washington.