LOS ANGELES (Reuters) - Police who found four people dead at a Southern California home said on Friday they believe the crime was a murder-suicide carried out by a man who fatally shot his girlfriend, her mother and teenage brother before turning the gun on himself.
But detectives were still trying to determine what led the 28-year-old man to kill his girlfriend and her family members, according to police in the city of Pomona, about 40 miles east of Los Angeles.
Officers responded to a home in Pomona on Thursday night after getting a call from a family member of the suspect who said he intended to harm everyone there, Pomona police said in a statement.
"The officers then forced entry and discovered four deceased persons in three different rooms all suffering from gunshot wounds," the statement said.
A preliminary investigation determined the suspect had a relationship with a 25-year-old woman who was among the dead.
"Detectives are still trying to determine the reason for the shooting and so far it appears that the suspect may have had a domestic dispute with his girlfriend and for unknown reasons he allegedly shot and killed his girlfriend and the other two family members in the house," Pomona police said.
The suspect was found dead of a self-inflicted gunshot wound in the same room as his girlfriend, and a handgun believed to be the murder weapon was found nearby, police said. Authorities did not immediately identify the suspect or any of the victims.
(Reporting by Dan Whitcomb; editing by G Crosse and Cynthia Johnston)