One of four people found dead in a suburban Southern California home killed the other three before committing suicide, authorities said.

On Wednesday, Orange County coroner's investigators are expected to release the names and relationships of the two male and two female victims and provide more information on how they died.

The bodies at the home in Mission Viejo were discovered by Orange County deputies responding to a 911 call from a relative, sheriff's Lt. Jeff Hallock said.

Hallock initially said no suspects were being sought and later disclosed that investigators had determined it was a murder-suicide. He provided only the genders of the victims and said nothing about their ages, relationships or which of them was believed to be the killer.

The bodies remained in the home for most of the day while detectives and coroner's officials examined the scene.

The house is located in a development called Pacific Hills, a modern neighborhood of two-story, upscale homes on winding streets.

Mission Viejo is a city of about 95,000 in the southern section of Orange County about 50 miles southeast of Los Angeles.