Appearing in court in Brooklyn, Jay Bryant, 52, admitted to playing a role in the fatal shooting of Jason Mizell, better known by his stage name Jam Master Jay, and faces up to 20 years in prison, the United States Attorney's Office for the Eastern District of New York said in a statement.
Bryant was accused of opening a locked fire-escape door to allow two armed men to enter Mizell's New York City recording studio where one of them shot the hip-hop star dead.
The two men, Karl Jordan and Ronald Washington, were found guilty in 2024 of murdering Mizell while engaged in drug trafficking.
A US federal judge last year overturned Jordan's conviction, ruling that prosecutors had failed to satisfactorily prove their case.
Mizell and his Run-DMC bandmates helped take hip-hop into the pop mainstream in the 1980s with hits like It's Tricky and a cover of Aerosmith's Walk This Way off the best-selling 1986 album Raising Hell.
As Mizell's showbiz success waned in the 1990s, he turned to dealing cocaine to help fund his music career, according to evidence presented at trial.
In 2002 Mizell bought cocaine for distribution in Maryland by Jordan, his godson, and Washington, his longtime friend, as well as others. Mizell cut Jordan and Washington out of the almost $US200,000 drug deal due to a dispute between Washington and one of the Baltimore co-conspirators, prosecutors alleged.
The disagreement led to Mizell's murder at the age of 37, with Jordan firing the shot that killed him, according to prosecutors.
