LOS ANGELES—Two members of the transnational gang MS-13, including a one-time “shot-caller” for the notorious criminal organization, will face 10 years to life in federal prison when they are sentenced later this year for their convictions in downtown Los Angeles on racketeering and drug charges.

José Balmore Romero, 49, and Erwin Alexander Melgar, 45, were convicted May 19 of single counts of conspiring to violate the Racketeer Influenced and Corrupt Organizations Act and conspiracy to distribute controlled substances. Melgar was also convicted of two counts of distributing methamphetamine.

Federal prosecutors said Romero was a leader, or “shot-caller,” for the overall gang in Los Angeles in 2013-14, overseeing the gang’s drug-trafficking activities and collection of extortion “taxes” and “rent,” which was distributed in part to members of the Mexican Mafia. He also issued gang orders such as the initiation of new members and assault of those who were in bad standing, prosecutors said.

Melgar, meanwhile, was a shot-caller for the Normandie clique of the gang based in Koreatown, according to the U.S. Attorney’s Office. In addition to overseeing that clique’s drug and other activities, he oversaw the operation of illegal after-hours clubs, or “casitas.”

U.S. District Judge Otis D. Wright II scheduled sentencing for Oct. 16.

Federal prosecutors said they have secured 28 convictions so far in the case targeting leaders of the gang in Los Angeles.