A gunman shot five people, killing three, early Thursday in an Hawaiian Gardens home.
The attack left a father, son and daughter dead and the mother critically wounded, authorities said.
Authorities said a man with an assault rifle and a can of gasoline entered his ex-girlfriend's residence and opened fire. A sheriff's deputy confronted and shot the attacker, investigators said.
Los Angeles County Undersheriff Larry Waldie said a deputy heard automatic weapons fire around 4 a.m. Thursday, grabbed his AR-15 rifle and confronted the gunman outside the home. The gunman then pointed his AR-47 at the deputy who fired twice and wounded the man.
Authorities said there were as many as 10 people inside the home. Six family members escaped by climbing through a window and hiding on a roof as a room-to-room
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"People jumped from windows and off the roof to escape," Waldie said, adding that if the deputy had not arrived, the suspect "might have killed 10 people."
The suspect was identified as 26-year-old Joseph Mercado. He is suspected of shooting and killing 25-year-old Serena Tarin, his ex-girlfriend, with an assault-style rifle in what appeared to be a domestic dispute involving a child custody issue, sheriff's homicide Lt. Don Slawson said.
Mercado also poured gasoline on an exterior wall but failed to light it with a match, Slawson said.