An 11-year-old is in surgery after being wounded in the shooting.
Five people are dead following a shooting in Southern California.
"We believe the man came over this morning, there was some kind of argument and he used a handgun to shoot his family before turning the gun on himself", said Lieutenant Matt Dobbs of SDPD. Police initially identified the eldest child as the lone survivor, but later said it was too early to tell.
The estranged wife had obtained a restraining order against the suspected gunman the day before, Dobbs said, although he added that it was still unclear whether it had been served when the shooting occurred.
When police got to the home in the Paradise Hills neighborhood, they broke through a front window and went inside after they saw an injured child laying on the ground.
He later told reporters that no one spoke during that call but dispatchers could hear arguing and someone being told to leave.
Police said they found the man, woman and their 3-year-old son dead at the scene.
Three other boys aged between five and 11 were transported to hospital for treatment where two other boys died.
"As you can imagine, I've been doing this nearly 32 years, these are the toughest calls you can respond to", Nisleit said during the press conference.
He said when officers arrived, they found a 3-year-old boy, a 29-year-old woman and a 31-year-old man dead inside. "To those that might be experiencing family violence, domestic violence there's resources". Police said the couple was separated and officers were called to the home earlier this month in reference to a disturbance over property. Police then said that they gave the woman information on how to file a restraining order.
Police found a gun in the house, but did not disclose its type, name of victims, or motive of the killer.
Some neighbors said they didn't know the family but often saw the children outside playing with their dog or riding their bicycles. He said counselling will be made available for any officers who need it.
"They were just living the kid's life on the outside, but who knows what goes on behind closed doors", said Gabriel Durazo, 36, who moved into the neighborhood about three years ago.