Two MS-13 gang members, including the alleged leader of the Somerville clique, were sentenced to heavy stints in prison for crimes surrounding the 2010 murder of a 28-year-old man in Chelsea.

U.S. District Court Senior Judge William G. Young sentenced Jose “Cholo” Vasquez, who also goes by “Little Crazy,” 31, of Somerville, to 25 years in prison to be followed by five years of supervised release. Vasquez is already serving a 17-year and 8-month sentence for a separate 2018 federal conviction.

Young also sentenced William “Humilde” Pineda Portillo, 31, to 16 years in prison, to be followed by three years of supervised release. Pineda Portillo, a noncitizen illegally living in Everett, is subject to deportation back to his home nation of El Salvador after his sentence.

Each man pleaded guilty to racketeering enterprise conspiracy, or RICO, charges that were brought last September as the third indictment in a sweeping MS-13 case first opened in 2017. The charges also connect them to the Dec. 18, 2010, murder in Chelsea of Joaquin Aguilar, of Allston. “Murder” is usually a state-level charge, so federal prosecutors often, as they did here, case it as violence related to RICO activity.

Federal authorities first connected Pineda Portillo to the planning of the murder and then connected Vasquez — who prosecution witnesses have described as the leader of the Trece Loco Salvatrucha (TLS) MS-13 clique in Somerville — to it as well, adding that unlike Pineda Portillo, Vasquez personally contributed to the 12 stab wounds Aguilar suffered.

Chelsea Police responded to 6th Street a little after 7 that December evening where they found Aguilar still conscious but bleeding from 12 stab wounds to his head and chest. He would be pronounced dead at Massachusetts General Hospital. Police tracked his blood trail to the site of the violence: under the Fifth Street on-ramp to Route 1 southbound in Chelsea.

“What these men allegedly did to their victims was particularly heinous — so much so that, over a decade later, the circumstances still stand out,” said Special Agent in Charge Jodi Cohen of the Boston FBI when announcing this and another murder-connected indictment in the MS-13 case.

MS-13, also known as La Mara Salvatrucha, has deep roots in El Salvador but has transnational operations with cliques pushing its reach throughout the U.S. and other countries like Honduras and Guatemala, according to court filings. Prosecutors say it is known as particularly violent, using “murder, assault, extortion, kidnapping, obstruction of justice and drug trafficking” to further its nefarious business.