Man Slain by Girlfriend’s Teen-Age Son, Police Say : Oxnard: According to authorities, killing occurred after argument between adults escalated to violence.

A 15-year-old Oxnard boy bludgeoned his mother’s boyfriend to death with a wooden stick early Saturday morning as the woman and her boyfriend were arguing, police said.

Roberto Vargas Ponce, 29, was pronounced dead at the scene from multiple blunt injuries to the head and upper body, Oxnard police said.

After the slaying, the youth was taken to the police station and later released to the custody of his mother, authorities said. They said the case will be submitted to the Ventura County district attorney’s office for review after an investigation is complete.

According to police, the 41-year-old Oxnard woman and Ponce had a history of domestic violence. Shortly before 3 a.m. Saturday, Ponce arrived at the woman’s apartment and an argument between the two quickly escalated into physical violence, authorities said.

The woman’s teen-age son came to his mother’s aid, striking Ponce repeatedly with a wooden stick and knocking him to the apartment’s front doorstep, police said.

They said officers and paramedics arrived on the scene soon afterward, but Ponce could not be revived.

The woman and her son live in a rear apartment on a tree-lined residential street. Residents said Saturday they were surprised by the homicide, as it seemed so out of character for the boy.

“He was really shy,” said Myeisha Erwing, 16, a next-door neighbor. “He didn’t bother anybody. He stayed by himself and wasn’t into gangs or anything.”

Other neighbors described the boy as having stuck close to his mother. They said he did not seem to hang out with other youths.

Myeisha said the woman and Ponce often fought.

“That’s why her son got mad,” Myeisha said. “He was just always watching this. I guess he just got mad.”

In a similar incident on Christmas Day, 21-year-old Isaias Guerrero was stabbed to death, allegedly by his mother’s ex-boyfriend, in the front yard of Guerrero’s Oxnard home.

Guerrero had tried to reason with Jose Socorro Jimenez, 32, after Jimenez showed up at the house at 3 a.m., yelling at Guerrero’s mother, police said. A fight soon erupted, and Jimenez stabbed Guerrero in the chest with a knife, police said.

Jimenez has been charged with murder and is being held on $250,000 bail.