The gunman who fatally shot a SWAT officer and three members of his own family suffered from "significant mental health problems" and had a juvenile criminal record, authorities said Friday.

Edwin Rivera, who was killed by a sniper as he attempted to flee the house hours later, first showed mental health issues when his mother died about a decade ago, said Deputy Chief Gary Brennan.

"These began shortly after the death of his mother when he was 10 or 11, and have become progressively worse," Brennan said.

Rivera had a juvenile arrest record dating to 2001 and had been arrested for driving without the owner's consent, grand theft and assault with a firearm, Brennan said. He was convicted of the latter charge and had served probation.

There was no evidence Rivera was a gang member, but police had been called to the house five times in one year for minor disturbances. There was also a drive-by shooting at the house in August 2006, Brennan said, but no one was injured.

Police identified the victims Friday as Rivera's father, 54-year-old Gerardo Rivera, and his brothers, 21-year-old Edgar Rivera and 25-year-old Endi Rivera. All three died of gunshot wounds.

The father's girlfriend hid in the house during the shooting, but escaped and was rescued by SWAT officers.

Randal Simmons, 51, was the first SWAT officer to be killed in the line of duty since the elite LAPD group was formed in 1967 and one of only 40 or so nationwide to die in that time, records show. He left a wife and two children.

Another SWAT officer, James Veenstra, also 51, was shot in the face and was recovering after surgery. The city's SWAT unit has 60 members.

Simmons' body was released to his family by the coroner shortly after the news conference. As the casket was loaded into a hearse, SWAT team members lined the roadway, standing at attention and saluting. A 50-car caravan, red lights on, accompanied the hearse to Angeles Funeral Home, where the body will be prepared for burial.

Veenstra hopes to be able to attend services Crenshaw Christian Faith Dome on Feb. 15, said LAPD Chief William Bratton.

The officers were shot early Thursday as they stormed the home in Winnetka, a middle-income neighborhood in the San Fernando Valley, after police received a 911 call from a man who said he had killed his family, authorities said.

Police arrived at the home shortly after 9 p.m. Wednesday after getting the 911 call and found two men dead and another who appeared to be wounded, Assistant Chief Michael Moore said.

After Simmons and Veenstra were shot, police retreated with their wounded colleagues — who fell within 12 feet of the doorway — and one of the victims, who was pronounced dead outside.

Brennan said the brothers were killed first. The body of Endi Rivera was found in the dining room and his brother, Edgar, was located in the kitchen. The father was found in a bathroom.

Two of them were shot in the head; the third victim was so badly burned, authorities could not determine where he had been shot.

Rivera used mattresses to hide as police shot tear gas inside the home and moved walls to find him.

Hours later, the house was burning. The blaze could have started when a stun grenade was thrown inside, police said.

Police later recovered a handgun and a shotgun from the home, Brennan said.

Simmons and his fellow officers acted appropriately, said Bratton.

"If there's a belief that a hostage is in danger, they will seek to make entry. ... SWAT did what we would have expected them to do," the chief said.