CONOVER, N.C. — Authorities say a man who was a suspect in a quadruple homicide in North Carolina has killed himself after a police chase in Utah.

Deputy Sheriff Coy Reid of the Catawba County Sheriff's Department said Wednesday the suspect killed himself after the chase in Washington County, Utah. The man's girlfriend also was killed.

Neither Catawba nor Washington authorities released their identities.

The suspect was wanted in last week's killings of Lisa Saephan and her three children – 20-year-old Melanie, 18-year-old Pauline and 4-year-old Cody – at their home outside of Conover.

Washington County authorities said a deputy spotted the car going south on Interstate 15 at about 11:20 Tuesday night. He followed it for about nine miles until backup cars joined him, and they tried to stop the car near Harrisburg Junction, about 17 miles north of the Arizona state line, the sheriff's office said.

The car hit another vehicle and ran off the road before stopping on an embankment. It burst into flames as deputies were approaching it, they said. The man and woman inside were already dead when deputies pulled them from the wrecked car, they said.