A second defendant in the Marley Lion murder case pleaded guilty Friday to lesser charges in exchange for his cooperation in prosecuting the man accused of shooting the 17-year-old.

Bryan Latrell Rivers, 29, of White Oak Drive in West Ashley pleaded guilty to voluntary manslaughter, attempted armed robbery and possessing a firearm with an obliterated serial number.

Voluntary manslaughter carries up to 30 years in prison. Attempted armed robbery is punishable by up to 20 years.

He had faced a murder count and lifetime imprisonment in the June 16, 2012, shooting outside a West Ashley bar, where Lion had stopped to sleep off a night of drinking.

Under the agreement, his sentence will be determined later based on how well he cooperates with the authorities. It’s unknown whether his deal requires testimony against Ryan P. Deleston, 32, of Cashew Street, the only man implicated in the shooting who is still charged with murder.

Deleston is expected to go to trial Oct. 7.

Solicitor Scarlett Wilson declined to comment about the development Friday because the case remains unresolved.

It came after a similar deal for 33-year-old Julius Perrell Brown of White Oak Drive, whose cooperation also likely will play a role in the alleged triggerman’s prosecution.

The police had accused Rivers, Brown and Deleston of scheming to rob Lion. Brown scouted out the sport utility vehicle that Lion was resting in before Deleston and Brown attempted to rob the recent high school graduate, according to the Charleston Police Department.

Detectives said Deleston walked up to the SUV. He retreated when its alarm sounded, but he returned and fired repeatedly into the vehicle, they alleged.

Like Brown, Rivers told prosecutors that he feared for his safety if information about his plea deal were publicized. Circuit Judge Stephanie McDonald agreed to seal the documents in both of their cases.

The move was steeped in history.

Brown had been a murder suspect in a 2000 slaying, but the main witness against him was fatally shot before his case went to trial. He was never implicated in that death, but the murder case against him from more than a decade ago fell apart.

George Ellis Brown, 28, of Corral Drive faces a charge of being an accessory after murder because the detectives said he knew details of the crime and didn’t divulge them to the police.

His relatives said that he had feared stepping forward because he had been shot while planning to testify in an unrelated murder trial.

Of the four defendants in Lion’s death, George Brown is the only one free on bail.

Reach Andrew Knapp at 937-5414 or twitter.com/offlede.