SAN FRANCISCO >> A California prosecutor said Monday he has filed murder charges that could lead to the death penalty for three young transients accused of gunning down a Canadian backpacker and a yoga instructor walking his dog.

The three arrived in California Monday evening and were taken to Marin County jail, the Marin County Sheriff’s Office said. They were arrested last week in Oregon.

Marin County District Attorney Ed Berberian said each suspect is charged with two counts of murder with special circumstances, including lying in wait. The suspects are 24-year-old Sean Michael Angold, 23-year-old Morrison Haze Lampley and 18-year-old Lila Scott Alligood.

An arraignment hearing for the three of them has been set for Wednesday, authorities said. It’s unclear if they have retained lawyers.

The body of Audrey Carey, 23, was discovered in San Francisco’s Golden Gate Park the morning of Oct. 3. She was shot once in the head, police said.

Investigators believe Carey was camping in the park, which was hosting a free, three-day bluegrass festival.

Tantric yoga instructor Steve Carter, 67, was found dead two days later along a popular hiking trail in Marin County, 20 miles north of San Francisco. He was still clutching the leash of his dog, the Marin County Sheriff’s Office said. The dog also was shot but is expected to survive.

San Francisco Police Commander Toney Chaplin said the same gun was used in both killings.

Authorities found the weapon when they arrested the suspects Wednesday outside a Portland, Oregon, soup kitchen, he said. The three also were found in possession of Carter’s car and some of Carey’s camping gear.

Chaplin said the gun was reported stolen from an unlocked car parked in San Francisco’s Fisherman’s Wharf neighborhood.

The Marin County district attorney added a special circumstance of multiple killings to each of the transient’s murder charges, enabling him to prosecute both shooting deaths in one trial.

"We will be monitoring the prosecution and will be cooperating with the Marin County DA’s office to bring justice to these victims’ families," San Francisco district attorney spokesman Alex Bastian said.

Carey had just left her home in the Canadian province of Quebec to go backpacking in the U.S. and Europe when she was killed.

Carter lived near the hiking trail where he was shot and drove there to walk his dog. He was living with friends while caring for his wife, who has cancer.