By DEREK KINNER

Associated Press

JACKSONVILLE, Fla. — A homeless man living in his truck helped police solve the fatal shooting of a black teenager by a white man during an argument over loud music outside a Jacksonville convenience store, according to testimony in the first-degree murder trial on today.

Shawn Lee Atkins testified that in November 2012 he witnessed a man shoot into a sport utility vehicle carrying four teens, killing Jordan Davis, 17, of Marietta, Georgia.

Atkins memorized the shooter’s license plate and gave the tag number to store employees.

Michael Dunn, 47, is being retried for first-degree murder after a jury convicted him of attempted second-degree murder for firing the shots but deadlocked on the murder charge.

The argument that day started when Dunn, who lives in Satellite Beach, Florida, was in Jacksonville for his son’s wedding and pulled into the convenience store, parking next to the SUV. Rap music was coming from the SUV.

Tevin Thompson, one of the other teens in the car, testified that Dunn appeared “a bit upset” and immediately addressed them. Thompson, who was 17 at the time and sitting in the front passenger seat, testified that Dunn said, “Turn the music down. I can’t hear myself think.”

Thompson testified that he turned down the music, but that Davis, who was sitting in the back, became angry and told him to turn the volume back up.

He testified that Davis and Dunn got into a shouting match, with Davis yelling profanities at Dunn.

Thompson said he heard Dunn say to Davis, “Are you talking to me?” and then he heard gunshots.

“He aimed it towards Jordan’s door, he started to fire,” Thompson said, adding that the man fired more than once.

The driver threw the car in reverse to get away, but Thompson said he kept hearing shots as they drove away.

Thompson said he never heard Davis or anyone else in the SUV threaten Dunn.

Prosecutors have said Dunn fired 10 times into the SUV.

Dunn’s attorneys say he feared for his life and fired the shots in an instant.

The homeless man, Atkins, said he saw Dunn fire the shots into the SUV and then get into a “police crouch” and continue firing as the SUV sped away.

Defense attorneys attacked Atkins as a convicted felon, saying he testified earlier that Dunn was leaning out of the car firing but now says he crouched outside the vehicle. Atkins is currently serving a seven-year term in prison for robbery.