LOS ANGELES — Los Angeles police Sunday are continuing to investigate a murder-suicide involving two men and two women who were found shot to death in a Granada Hills home.

The shooting was reported at 6:50 p.m. Saturday in the 11600 block of Lerdo Avenue, north of the Ronald Reagan (118) Freeway next to Zelzah Park, LAPD Officer Rosario Cervantes told City News Service.

Arriving officers knocked on the door, but no one answered, so they forced entry and were met by a witness who directed them to the deceased people, Cervantes said.

A woman believed about 80 years old and a man and woman in their late 40s were found shot to death. A man in his late 80s, believed to be the shooter, was found dead in a different area of the house from an apparent self- inflicted gunshot wound, investigators said.

“They all appear to be family,” Lt. Blanca Lopez of the LAPD’s robbery-homicide division told the Los Angeles Times. “This is an isolated incident.”

Investigators said the witness barricaded themselves in a room during the shooting and called police, but no further details were released.

It was also unclear whether the witness was part of the family.

Video from the scene showed a large police presence in the neighborhood as the shooting was investigated.

No information on the victims’ identities or a motive has been released.