Rigoberto "Ninja" Mejia, 32, admitted today he pumped bullets into Cristofer Perez de la Cruz, 16, as other MS-13 members were busy stabbing the teen.
Mejia, a Salvadoran national, was a full-fledged member, or "homeboy" of MS-13's Somerville-based Trece Locos Salvatrucha gang, when they set out to murder a member of the rival 18th Street Gang as part of an escalation in a war between the two, ordered at an MS-13 conclave in Richmond, VA the month before. The man who ordered the murders of 18th Street Gang members pleaded guilty last month.
Perez de la Cruz's body, missing a hand, was found dumped on Falcon Street on Jan. 10, 2016.
Nine days later, federal and local authorities announced a series of raids that ultimately resulted in 61 arrests of alleged Boston-area MS-13 members.
As part of a plea deal, Mejia agreed to a sentence of 330 months - 27 1/2 years. U.S. District Court Judge F. Dennis Saylor, who can accept or reject the proposed term, set sentencing for July 24.
Mejia is the 44th MS-13 member to either plead or be found guilty following the arrests.