A woman told police she can’t remember what happened when her car struck and killed her fiance as he was walking home from a bar in Ashland, the police chief said Sunday.

Ashland police believe Nancy Lauren McKay, 41, drove her car into George Tozier Sr., 48, from behind while he was walking on Route 227 early Saturday.

She then broke into a nearby home and hid under blankets on a couch until police found her and arrested her, Police Chief Cyr Martin said Sunday.

She was charged with aggravated operating under the influence.

Martin said additional charges related to Tozier’s death may be brought against McKay depending on the outcome of the department’s investigation.

He said police were trying to piece together what happened in the hours surrounding the Ashland man’s death, but with McKay saying she doesn’t remember what happened, many questions linger.

Tozier and McKay had been living together for two years and were planning to marry.

Police said the two had gone to Freem’s Bar and Grill on Main Street in Ashland on Friday night.

Police on Sunday were not sure whether the couple had a dispute, but Tozier left the bar on foot and tried to walk to his house, which is five miles away on the Frenchville Road, Route 227.

Tozier was less than half a mile from town when the couple’s black 1998 Chevy Cavalier came up behind him.

“The person that we are quite certain was driving went around the corner and hit him,” Martin said.

Both McKay’s car and Tozier were heading east. Police said the vehicle hit him from behind. Martin said Tozier landed on top of the car and was killed instantly.

His body ended up along the eastbound lane. McKay’s car veered left across the highway and wound up on the side of the westbound lane. The car was a total loss.

“We aren’t 100 percent sure yet if she was driving,” Martin said. “She’s saying she wasn’t.”

He said there are no other suspects in the case.

Police received a call about the crash about 2 a.m. Saturday. Officer Matthew Cummings, who is investigating with the chief’s assistance, was the first officer on the scene. Martin estimated that traffic was stopped for three hours on the road as officials cleaned up the scene.

Not long after police responded, they received a report of a possible burglary at a home on the Frenchville Road.

“Somehow, someone noticed there was a house with a light on when there shouldn’t have been,” Martin said. “We found McKay hiding on the couch under some blankets. … She was in and out of it.”

McKay apparently had broken a windowpane on the back door of the home to get inside. Martin said McKay does not recall being in the house.

McKay was arrested at the house and charged with aggravated OUI. She was unable to make bail at the Ashland Police Department – it was set at $5,000 cash or $10,000 surety – and was taken to Aroostook County Jail in Houlton.

Along the way, she was taken to a hospital to have her blood alcohol level tested. Martin said those results weren’t back Sunday, but that police believe McKay was intoxicated when they found her.

Police said McKay did not have any injuries, but had minor scratches and bruises which they believe she received in the car crash.

The Maine State Police were assisting Ashland police with the accident reconstruction.

It was not clear Sunday where McKay would make her first court appearance, although it is scheduled for Tuesday.