David James, a former personal assistant to Diddy, is continuing his testimony in the disgraced rap mogul’s federal sex trafficking and racketeering trial in NYC Tuesday, and he told the jury about a harrowing incident in L.A. involving another titan of the music industry.

James was asked about a 2008 incident at a Mel’s Diner, a restaurant in L.A., involving former rap mogul Suge Knight (who’s currently in prison for an unrelated crime). James described driving a Lincoln Navigator SUV to get cheeseburgers, accompanied by a man named D-Roc.

James testified D-Roc recognized Suge Knight at the location, and went over to talk … but Knight apparently didn’t recognize D-Roc, who said “I’m Biggie’s boy,” referring to slain rapper Notorious B.I.G. (who was murdered in the city in 1997).

James said that’s when they noticed four black SUVs on different sides of the parking lot, and he said he saw someone hand Knight a gun. D-Roc suggested they leave, and they did.

He says they drove back to Diddy’s house, where he saw Cassie crying … and Diddy got into a different vehicle with James. James testified he saw three guns on Diddy’s lap when they drove back to Mel’s Diner, but Knight was gone … but Diddy ordered him to drive around the block.