Rubbing his hands on his thighs and exhaling a deep breath, defendant Keith Kellum pleaded guilty to second-degree murder Friday, a decision that could send him to prison for the rest of his life.

Kellum, 24, was set to face a Sonoma County jury on Monday with his co-defendant, Bradley Blackwell, 19, in the killing of 20-year-old Uriel Carreno in his Petaluma garage apartment in February 2007.

Blackwell was present in court Friday afternoon as Kellum admitted his involvement, and then blamed Blackwell for the killing. Blackwell will now head to trial alone. He faces a possible sentence of life without parole if convicted. Although he was under 18 when the killing occurred, Blackwell is being prosecuted as an adult.

Damning evidence presented at a preliminary hearing in 2007 and at pretrial hearings this month apparently pushed Kellum toward a deal that allows at least a small hope of eventual release.

In a hastily called hearing Friday afternoon, Kellum appeared nervous as he filled out forms waiving his right to appeal his guilty plea. He confessed his involvement.

?Me and Mr. Blackwell went to Petaluma to a drug dealer?s house...? to do a drug rip-off, he said, as he described the events of the rainy Feb. 7 two years ago, on a Joan Drive home in east Petaluma, a block from a block from Lucchesi Park.

?I kicked the door in and Mr. Blackwell shot and killed a man,? he said.

Under questioning from his attorney, Martin Woods, Kellum said he had ?absolutely nothing? to do with a gun and did ?absolutely not? fire a gun.

Blackwell, with his attorney, Roy Miller next to him, watched from about 12 feet away.

In statements to police, the defendants, both from Rohnert Park, each blamed each other for the murder.

Kellum told detectives Blackwell kicked Carreno?s door in and shot him when Carreno ? on his knees ? reached for a metal pole. Blackwell said Kellum kicked in the door and shot Carreno.

One of Blackwell?s brothers led detectives to where he said he?d buried a towel-wrapped gun and shoes possibly worn to kick in Carreno?s door. A parolee testified that he and the defendants returned to Petaluma after the killing to clean up any shoe-print or fingerprint evidence that may have been left behind.

The parolee, who is now in jail and facing a prison sentence in Michigan, testified Thursday in a pretrial hearing that Blackwell told him that he shot Carreno. He said Blackwell later told him Kellum also shot Carreno twice.

Because Blackwell and Kellum gave statements implicating each other, two juries had been impaneled to hear evidence against the defendants. Kellum?s jury will now be dismissed.

Blackwell?s trial is set to begin Monday morning in front of Judge Ren?Chouteau.

Kellum is set to be sentenced on May 11.