Barreto, 32, faces a possible death sentence if the jury finds him guilty of first-degree murder in the Jan. 10, 2012, incident in which he fired into a Toyota Corolla crammed with seven teens belonging to the Kick Ass Boys, a local street gang. Three occupants of the Toyota - Joshua Soto, 14, Dante Lugo, 14, and Javier Orlandi, 16 - were killed, and the 16-year-old driver was wounded in the neck.
Barreto testified last Friday that he fired in self-defense when he confronted the teens in an alley behind his house on the 4000 block of Neilson Street about 10:30 that night.
Defense attorney Jack McMahon said the seven teens had menaced Barreto's stepson, Benjamin Torres, for months.
The night of the shooting, McMahon said, the Toyota had been cruising the block in front of Barreto's house trying to lure his stepson out to fight.
Instead, Barreto got a semiautomatic pistol and went into an alley behind the house where he spotted the idling Toyota. Witnesses said Barreto fired 10 to 12 shots at the car at close range as the driver frantically tried to drive off.
Assistant District Attorney Jude Conroy argued that Barreto inserted himself into the volatile situation. Conroy said none of the teens in the car were armed and Barreto kept firing even after the car was "in full retreat mode."
If the jurors find Barreto guilty of first-degree murder, they would begin hearing evidence to determine whether to sentence him to life in prison without parole or death by lethal injection.