A gunman has killed five people - including the mother of his two children and her boyfriend - in entered a western Arizona home before fleeing with the children to Southern California where he killed himself.
The shootings on Saturday night occurred as 23-year-old Deborah Langstaff and friends were celebrating her boyfriend's birthday, Lake Havasu City police Sgt. Joe Harrold said. In all, six people died.
Police went to the Lake Havasu City home after receiving an emergency call at 11.57pm from a woman who said an intruder had shot several people. Officers responding to the home said they found the bodies of Ms Langstaff, Primo Verdone - who had just turned 24 - Russell Nyland, 42, and Ashley Nyland, 20.
Two others were wounded, but 20-year-old Brock Kelson died of his injuries early on Sunday. Deborah Nyland, 44, is in intensive care at a Las Vegas hospital.
Lake Havasu City police issued an Amber Alert for the children and traced the alleged gunman, 26-year-old Brian Diez, to a property in California several hours after the shooting.
At about the same time, San Bernardino County Sheriff's Department deputies were sent the home about a reported suicide. Officers found Diez dead of a self-inflicted gunshot wound at about 3.30am, authorities said.
The two children - a 4-year-old and a 13-month-old - were unharmed at the house with family members, police said.
Ashley Nyland was a friend of Ms Langstaff's, and Russell and Deborah Nyland are Ashley's parents, Sgt Harrold said. Mr Kelson was Ashley Nyland's boyfriend, he said.
Diez fathered the two children with Deborah Langstaff during a long-term relationship, but the couple had been estranged, Lake Havasu City police said.
Diez was arrested on August 13 for violating an order of protection Ms Langstaff had against him that prohibited him from contacting her or the children, Sgt Harrold said. Diez had approached her and talked to her, but didn't make any threats, he said.