CARIBOU – A Presque Isle man was in critical condition Tuesday at a Bangor hospital after he shot himself in the head during a 45-minute early morning standoff with police.

Robert Theriault, 29, who recently returned to northern Maine from Glen Burnie, Md., was being sought early Tuesday morning by police investigating a home invasion in which a woman allegedly was assaulted and threatened by Theriault. The woman was not injured.

Maine State Police Trooper Carman Lilley, who was very close to Theriault when the shooting occurred in a Caribou field, was splattered with blood. As a precaution, Lilley was treated for blood-borne pathogen contamination at Cary Medical Center and then released.

Theriault was taken to the Cary Medical Center and later flown to Eastern Maine Medical Center in Bangor, where he remained Tuesday afternoon. Lt. Darrell Ouellette, Troop F Maine State Police commander in Houlton, said the woman involved in the incident was able to fight off Theriault, escape and call police from a neighbor’s home.

“He knew where he was going, and he knew his victim,” he said. “They had some kind of relationship in the past. She was assaulted and threatened by Theriault, who had a handgun,” Ouellette said. “We don’t know the motive for the incident and the investigation is continuing.”

Ouellette said Theriault was armed with a .357-caliber revolver when he entered the Limestone Street woman’s home at about 2:30 a.m. Police believe it was the same weapon he used to shoot himself nearly 21/2 hours later, at about 5 a.m. No other weapons were found.

The woman, Ouellette said, did not live alone in the single-family home. She was the only person assaulted and threatened.

The Caribou Police Department was the first to respond to the woman’s emergency call around 3 a.m. The caller told police that a man had entered her private home and attacked her. She told police she fought him off and escaped, going to a neighbor’s home to call police.

The state police were called by the Caribou Police Department at about 4 a.m. for assistance. Local police wanted to use a police dog to pick up a trail.

Ouellette said the dog arrived at the scene and took police to a field off Limestone Street. Police found Theriault behind some bushes about half a mile from where the home invasion took place.

The area is near the Route 1 bypass.

Ouellette said two state troopers, two officers from the Caribou Police Department and a Maliseet police officer talked with the man for about 45 minutes before the shooting occurred at about 5 a.m.

Theriault reportedly threatened suicide several times while police talked with him. Ouellette said there were eight officers involved in the incident by the time Theriault turned the gun on himself.

Theriault has no police record in Maine, according to Ouellette.