Man pleads guilty in Baldwin Park triple-slaying

BALDWIN PARK -- A Baldwin Park man admitted Thursday to murdering his mother, a woman next-door and the neighbor's 4-year-old daughter during a 2008 shooting spree, officials said.
Roy Perez, 30, pleaded guilty to three counts of murder for the deaths of 47-year-old Alicia Perez, 31-year-old Dalmy Mata and 4-year-old Briana Mata at a pretrial conference in Pomona Superior Court, court officials said.
He also pleaded guilty to attempting to murder Dalmy Mata's two other children, then ages 9 and 14, who were shot and wounded in the Feb. 25, 2008, attack in the 14500 block of Rockenbach Street in Baldwin Park.
"Perez had an argument with his mother," Lt. Dan Rosenberg of the Los Angeles County sheriff's Homicide Bureau said. "As the dispute continued, he retrieved a handgun and shot her."
"After the shooting, he went next-door and began shooting members of the Mata family," the lieutenant said.
Alicia Perez was shot more than a dozen times, Los Angeles County District Attorney's Office spokeswoman Shiara Dávila-Morales said. Dalmy Mata was shot once in the head and once in the neck, and Briana Mata was shot once in the head.
Alicia Perez, Dalma Mata and Briana Mata were all pronounced dead at the scene.
When police arrived, Rosenberg added, they found Perez standing in front of the home, still clutching the 9mm handgun he used to carry out the shooting.
The children who were wounded in the shooting -- Kimberly and Edwin Mata, have since recovered from their wounds and are "doing well," Dávila-Morales said.
The prosecutor handling the case could not be reached directly for comment Thursday.
Roy Perez lived with his mother at the home, officials said.
Though an argument between Roy Perez and his mother led to her shooting, prosecutors and sheriff's investigators said they did not know why Perez chose to attack his neighbors.
"The motive remains unclear," Dávila-Morales said. "(Perez) does have a history of mental health problems."
Sheriff's homicide investigators and Perez's family members have said Perez has displayed erratic and violent behavior in the past and had been placed on a 72-hour psychiatric hold more than once.
Perez faces three consecutive life sentences without the possibility of parole, as well as an additional consecutive 139 years in prison when sentenced on January 14, Dávila-Morales said.