Los Angeles County prosecutors will ask a judge Thursday to free a man convicted seven years ago of killing a college student, citing new doubts about his guilt.

Raymond Lee Jennings is serving 40 years to life in state prison following a 2009 conviction.

"My office has been presented with credible new evidence that brings this conviction into question," District Attorney Jackie Lacey said in a statement Wednesday.

Lacey said her office will ask a Superior Court judge to release Jennings, 42, on his own recognizance "in the interest of justice" while the DA's Conviction Review Unit, formed last year, completes an investigation.

The DA's office did not provide details of the new evidence. But Jennings' attorney, Jeffrey Ehrlich, said the unit, at his request, had decided to reopen the murder investigation.

Only two men were at the scene at the time of the Feb. 22, 2000, killing in Palmdale, he said.

"They only investigated one man, Ray Jennings. They have finally decided to investigate the other one," Ehrlich said Wednesday. "That reopened investigation has generated new leads that they are actively pursuing."

The DA's office has agreed that if the new investigation finds nothing tying Jennings to the killing, in 60 days prosecutors will agree to have the court throw out his conviction, Ehrlich said.

Ehrlich said he was unsure whether Jennings was aware of the decision, but he has always proclaimed his innocence. "He's been in prison for 11 years. It has been remarkable about how resilient he has been," Ehrlich said.

Jennings was working as a security guard when Michelle O'Keefe, 18, was shot in a car in a park-and-ride parking lot in Palmdale, a desert town northeast of Los Angeles.

O'Keefe, a student at Antelope Valley College, had returned from Los Angeles where she had worked as an extra in a music video. She was shot several times.

Jennings, an Iraq War veteran with no criminal history who was studying to become a U.S. marshal, said he was 400 feet away when he saw O'Keefe's car rolling backward and heard gunshots but said he never saw any attacker.

After two previous trials ended in deadlocked juries, Jennings was convicted of second-degree murder.

Members of O'Keefe's family were on hand when Jennings was sentenced in 2010.

"I sit here as an innocent man," Jennings told them, adding that "as Christ as my Lord and savior, I will stand before God and this is one sin that I will not be judged for."