LOS ANGELES, Jan. 5 (Xinhua) -- A murder-suicide shooting incident occurred Friday morning in Saugus, a mall town of located about 70 kilometers northwest of the Los Angeles downtown, in which four people were killed.

According to a video posted online, assistant chief Ed Winter of the Los Angeles County Coroner's Office confirmed at a news conference outside the residence where the bodies were found that four people were dead, investigators believed three of them were shot to death and the fourth dead could be the killed who suicide later.

He said the four victims appeared to be members of a family, including approximately 50-55 years old suspect, his wife was 40-50 years old, a woman in her early 20s and a preteen boy.

However, the detectives were not sure so far how long the bodies were in the house and motive of the shooting case, saying they discovered the bodies when they responded to the home after received a call for a welfare check Friday morning.

Rodney Moore of the Los Angeles County Sheriff's Department's Homicide Bureau said no neighbors reported hearing gunshots and he had no information on why the welfare check call was made by a family friend.

Officials urged the public to avoid the area as a shooting investigation remained ongoing. The online information showed the address is registered as a day care center.