The 37-year-old DJ, whose real name was Jason Mizell, was shot in the head in his New York recording studio in 2002.

He was part of one of the best-known rap acts of the 1980s.

Uriel "Tony" Rincon was in the studio when Mizell was killed. He was also wounded in the gunfire.

On Wednesday, Mr Rincon pointed to who he believed was the killer - Karl Jordan Jr - in one of the world's most infamous killings in hip-hop history.

Describing the moment of the DJ's death, Mr Rincon said Jordan "kind of walked directly to Jay and gave, like, half a handshake, with an arm.

"And at the same time, that's when I hear a couple of shots," he told the jurors at the New York City courtroom.

In 2020, Jordan, who was Mizell's godson, and the star's childhood friend Ronald Washington, were charged with murder - to which they have pleaded not guilty.

Mr Rincon said he was looking down at his ringing phone when the gunfire erupted, then looked up again.

"And then I see Jay just fall," he said.

Mr Rincon then described the pain in his leg having realised he had been shot and that Jam Master Jay was severely wounded.

"I'm trying to tend to my wound, and at the same time, I'm trying to give Jay attention - asking him is he OK? Can he talk? And he is just not responding," Mr Rincon said.

He said that during the shooting, Washington was at the studio door, telling another witness to get on the ground and stay there.

Prosecutors previously said Jordan and Washington were motivated by greed and revenge, after being cut out of a lucrative cocaine deal set up by Mizell.

If convicted, they could face at least 20 years behind bars.

The death penalty is not being sought for either defendant.

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All you need to know about the trial

What does the defence say?

Jordan's lawyer, John Diaz, said his client wasn't even at the studio on the night of the shooting.

His legal team has said in court documents that Jordan, then 18, was at his pregnant girlfriend's home at the time of Mizell's death and witnesses could state that.

Washington's lawyer Ezra Spilke argued the case was held together with "tape and glue" and stated prosecutors have "no clue" who killed the DJ.

A third man, Jay Bryant, was arrested and charged in 2023 and he will be tried separately in 2025 or 2026.

What led Rincon to testify?

One of the lawyers, Mark DeMarco, said while questioning Mr Rincon that the witness repeatedly told investigators for years that he had not quite seen and could not identify the gunman.

"I was confused and scared and not trusting a lot of things that were happening," Mr Rincon said.

"I didn't understand what I saw, and I didn't understand why or who - because, again, it was somebody I knew. So that's why it was hard for me to grasp," he said.

He finally named Jordan and Washington to authorities in 2017.

When asked why he finally did so, Mr Rincon said he thought of Mr Mizell's surviving family.

"I felt that his wife and his children needed closure, and I felt that they should know what took place," he said.

Run-DMC also included rappers Joe "Run" Simmons and Darryl "DMC" McDaniels, and they had hits such as King Of Rock, It's Tricky and a reworking of Aerosmith's Walk This Way.