Sonoma County prosecutors said Monday they will not seek the death penalty against a 19-year-old Santa Rosa man accused of two gang killings, citing his youth and lack of a criminal record.

Raul Vega is charged with the stabbing death of Juan Carlos Angel-Esparza, 20, of Santa Rosa on the grounds of Kawana Elementary School on Jan. 8.

Vega has also been identified as the suspected shooter in a Jan. 12, 2010 Contra Costa County freeway shooting of Vallejo musician Dewey Tucker, 24. Prosecutors said Vega and three co-defendants mistook Tucker for a gang rival. Tucker was a bassist for Grammy Award winning performer Lauryn Hill.

"We're not trying to give any of these guys a merit badge, but the decision has been made that we are not going to seek the sanction of death," prosecutor Bob Waner said outside a court hearing Monday morning.

Vega appeared in court briefly alongside Christopher Mancinas, 30, Hector Barragan, 29, and Javier Carreon-Lopez, 20, all of Santa Rosa. The four now face a maximum punishment of life in prison without parole.

Vega asked Judge Arthur Wick to replace his court-appointed lawyer, Kathy Hernandez. He set a hearing for Wednesday on the matter.

Relatives of Angel-Esparza wore T-shirts displaying his picture. His girlfriend and mother to his young son, Elisha Donahue, said Vega appeared "cocky" in court.

"It's just sickening," she said. "Last time he was smirking."

Prosecutors have said Vega is a participant in the sureno street gang. A search showed no significant adult criminal record. Any offenses committed while he was a minor would be sealed.

Of the other defendants, only Mancinas has felony convictions — one for assault and another for theft. Also, he has a pending felony drugs charge.

In letters dated Friday, District Attorney Jill Ravitch acknowledged some of the defendants' gang backgrounds but said a decision was reached to not seek the ultimate punishment.

"It doesn't in any way minimize the seriousness of the offense," Ravitch said in a phone interview Monday. "We will be prosecuting this case vigorously."

Waner said the victim's family was consulted on the decision.

The Kawana school killing apparently arose from a growing rivalry between subsets of the same gang feuding over the Moraga Drive territory.

Witnesses said Vega and Angle-Esparza squared off near the school's baseball fields sometime around nightfall as others stood by. They scattered at the sound of sirens. When police arrived, Angel-Esparza was lying unresponsive and later died of a direct stab wound to the heart.

Vega was arrested two days later.

In the aftermath of the stabbing, Vega was charged with the three others in the Tucker shooting. Court documents say the four drove to Contra Costa County to seek retaliation against a rival after learning of threats made against Barragan.

Tucker was shot in the head as he drove to a rehearsal along I-80 near Crockett.

CHP investigators named the defendants just after the Kawana stabbing. Prosecutors said the two killings are related but they would not disclose further details.

All are charged with gang allegations and special circumstances that could put them behind bars for life if convicted.

A preliminary hearing is set for June 2.