The sole survivor in a weekend shooting that left five people dead in western Arizona was in fair condition Monday, and authorities are hopeful she can help explain what led up to the slayings.

Deborah Nyland was transported Sunday to Sunrise Medical Center in Las Vegas, where she remained a day later, according to a hospital spokeswoman. The 44-year-old called 911 just before midnight Saturday to report an intruder had shot several people in a Lake Havasu City home.

Authorities say Brian Diez, 26, entered the home and fatally shot five people — including the mother of his two children and her boyfriend — before fleeing with the kids to Southern California, where he killed himself.

Lake Havasu City Police Sgt. Joe Harrold said authorities are awaiting the results of autopsies to determine how many shots were fired. He said investigators will follow up with Nyland when the time is appropriate.

"Our detectives will talk to as many people as possible to try and re-create the events and get as much information as possible to get some answers as to why this tragic event happened," he said.

The shooting occurred as Deborah Langstaff and her friends were celebrating her boyfriend's birthday. Officers responding to the 911 call Saturday night found the bodies of Langstaff, Primo Verdone — who had just turned 24 — Russell Nyland, 42, and Ashley Nyland, 20, a friend of Langstaff.

Brock Kelson, 20, Ashley Nyland's boyfriend, died of his injuries early Sunday. Deborah Nyland — the mother of Ashley Nyland and wife of Russell Nyland — remained hospitalized.

According to Arizona court records, Diez was involved in about two dozen previous cases, including several traffic cases.

Police say he violated a restraining order earlier this month when he approached Langstaff and talked to her, but he made no threats, Harrold said. Diez had been ordered to stay away from Langstaff and their children after being accused of slapping their infant son, police said.

Langstaff and Diez had dated on and off for about five years, Harrold said.

Their children — a 4-month-old and a 13-month-old — were found unharmed in California and are staying with family, said Jodi Miller, spokeswoman for the San Bernardino County, Calif., sheriff's office.

The sheriff's office, responding to a reported suicide, found Diez's body in a vehicle outside his sister's Rancho Cucamonga, Calif., home early Sunday.

A man who answered the phone at the home Monday said the family would have no comment.