A homeless woman who in May was violently beaten by a man with a hammer on a Santa Rosa sidewalk, according to police, died Thursday from the extensive injuries she suffered in the attack.

Stephanie Janelle Ashton, 45, was struck repeatedly in the head and never regained consciousness after the May 7 assault, near Montgomery Drive and Second Street, police said.

Robert Holladay, a 56-year-old homeless man, was arrested by Santa Rosa police shortly after and was booked into Sonoma County Jail for attempted murder and kidnapping.

He remains in custody with bail set at $1 million. Holladay’s charges will be updated to reflect the case has now become a homicide, said Lt. Mike Lazzarini.

Since the attack, Ashton had been treated at local hospitals and long-term care facilities, Lazzarini said.

“She never regained consciousness. It was a long and tragic ordeal,” he said. “Four months after, she passes away. It’s horrible.”

After the assault, Holladay pulled Ashton into his SUV and drove off, a witness said at the time. Santa Rosa police then stopped Holladay on 4th Street by Farmer’s Lane. Officers reported he had blood on his hands and clothing.

Holladay was “nonchalant” about being pulled over and said he was the only one in the car, Sgt. Josh Ludke said at the time.

Officers found Ashton on the van’s back floorboard, “crumpled up ... (and) bleeding to death,” Ludke said in May.

She was transported to Santa Rosa Memorial Hospital.

Officers found a bloody hammer, the suspected assault weapon, inside the SUV, police said.

Both Ashton and Holladay lived in their cars and had parked near each other before the attack, police said. They knew each other, but the extent of their relationship was still unknown, police said.

Police did not offer any additional details about a possible motive in the attack.

You can reach Staff Writer Nick Rahaim at 707-521-5203 or nick.rahaim@pressdemocrat.com. On Twitter @nrahaim.