The Santa Claus killer who slaughtered nine people at a Los Angeles party on Christmas Eve was taking revenge on his ex-wife and her family after a bitter divorce.
Police say Bruce Pardo, 45, an unemployed aerospace engineer, had just been through contentious divorce proceedings with his wife Sylvia - who was reported to be among his victims. The house was that of her parents, who also appear to have been killed.
Pardo, who had also lost his job in October, was later found dead of self-inflicted gunshot wounds.
About 25 people are believed to have been at the party in Covina when Pardo knocked on the door dressed in a Santa suit. An eight-year-old girl who opened the door to greet him was shot in the face, before he went into the house firing several weapons.
He then used a home-made device to spray the rooms with a highly flammable gas consisting partly of racing car fuel. The subsequent explosion gutted much of the house, making it difficult to tell whether the victims died of gunfire or were burnt to death.
Many of the bodies were burnt beyond recognition. Two girls, including the one who answered the door, have been treated for gunshot wounds.
Pardo himself suffered third-degree burns in the blast, which melted the Santa Claus outfit onto his body. He then fled to his brother's house about 65 km away, where he killed himself.
Killer had planned to flee
Some $17,000 in cash and airline tickets for a flight from Los Angeles to Canada were found on Pardo's body, Police Chief Kim Raney told a news conference.
A rental car parked nearby was found to have been booby-trapped with the remnants of the Santa suit rigged to a home-made bomb, which ignited when bomb disposal experts tried to defuse it. But no one was hurt in the blast, Raney said.