RIVERSIDE, Calif. — A Virginia sheriff’s deputy who police say traveled to California to kill three family members of a 15-year-old girl he tried to sexually extort online killed himself with a government-issued firearm, authorities said Saturday.

Austin Lee Edwards, 28, drove across the country and on Nov. 25 killed the girl’s mother and grandparents and set fire to their home in Riverside, a city about 50 miles (80 kilometers) east of downtown Los Angeles, authorities said.

That same day, Edwards died by suicide during a shootout with San Bernardino sheriff’s deputies. The teenage girl was rescued.

“Our detectives determined the gun used was Edwards’ department-issued semi-automatic service pistol,” sheriff’s spokeswoman Gloria Huerta said in a statement.

The Riverside Police Department, which is investigating the deaths of the girl’s family members, has not said how they were killed.

Edwards, a resident of North Chesterfield, Virginia, appears to have posed online as a 17-year-old boy to engage in a romantic relationship with the girl and obtain her personal information by deceiving her with a false identity, known as “catfishing,” police said.

Authorities said the girl stopped communicating with him after he asked her to send him nude photos of herself.

Edwards was a former Virginia state trooper and was a sheriff’s deputy in Washington County, Virginia, at the time of the killings.

Both law enforcement agencies have said they found no warning signs about Edwards before he was hired. But a police report from the Abingdon Police Department in Virginia shows he was detained in 2016 for a psychiatric evaluation over threats to kill himself and his father, years before he joined law enforcement.

On Thursday — a day after the Los Angeles Times broke the news about the mental health episode — the Virginia State Police said a recently completed review showed “human error” resulted in an incomplete database query during the hiring process.

The Washington County Sheriff’s Office did not respond to calls seeking comment on the 2016 episode.