Jurors convicted a 20-year-old Santa Rosa man Friday of first-degree murder and voluntary manslaughter in two separate slayings tied to a gang turf war.

The verdicts came in the more than month-long trial of Raul Vega, charged in the 2010 drive-by shooting of Vallejo musician Dewey Tucker, 24, and last year's stabbing of Juan Carlos Angel-Esparza, 20, of Santa Rosa, on the grounds of Kawana Elementary School.

Jurors found Vega murdered Tucker when he drove alongside him on Interstate 80 and fired after mistaking him for a gang rival.

Also, they convicted Vega of the lesser charge of voluntary manslaughter in Angel-Esparza's slaying, accepting Vega's argument that the killing happened in self-defense.

Prosecutors, who were seeking two first-degree murder convictions, played Vega's taped confessions to police at trial.

Now the man portrayed as an up-and-comer in the Santa Rosa gang underworld faces a mandatory sentence of life in prison without parole at an upcoming hearing.

Vega stared in silence and seemed to struggle for words when his lawyer asked if he would return to court Thursday to set a sentencing date.

The unrestrained man was led back to jail by deputies as Angel-Esparza's family members looked on. Maria Angel, who wore a T-shirt emblazoned with her dead brother's picture, declined to comment.

Jurors waiting to leave the courthouse also declined to comment. They deliberated about seven days, reaching verdicts on all but one allegation — that Angel-Esparza was killed for the benefit of a gang.

The specter of gang violence added to trial tensions.

On Friday a woman juror broke down in tears before Judge Dana Simonds after recounting a chance meeting in a dentist's office with a Vega family friend. She said the friend greeted her and acknowledged seeing her on the panel.

"I just kind of felt exposed, like someone knows my identity," the woman sobbed.

Both sides agreed to keep her on the jury.

Vega was the second of four suspects to be tried in Tucker's murder. Christopher "Spider" Mancinas, 29, was acquitted of murder earlier this year. Hector Barragan, 28, and Javier Carreon-Lopez, 20, pleaded no contest to lesser charges.

Prosecutors said the four drove to Vallejo on Jan. 12, 2010 to get revenge for the killing of a friend. They followed the wrong car out of the parking lot and killed Tucker, a bass player for hip-hop artist Lauryn Hill, as he drove to a music rehearsal.

The case went unsolved for a year until Angel-Esparza was stabbed to death in a fight with Vega at the southeast Santa Rosa school. Vega confessed to the earlier slaying but said he was defending himself from Angel-Esparza, who attacked him with a knife.

Vega recanted part of his story on the witness stand, saying he was not present when Tucker was killed.