MATTAMISCONTIS TOWNSHIP — A man armed with a rifle is dead after spending just over four hours threatening to shoot himself in a rented U-Haul truck pulled over on Interstate 95 just south of the Lincoln exit.

“We certainly suspect this is a self-inflicted gunshot wound,” said Stephen McCausland, spokesman for the Maine Department of Public Safety.

Maine State Police confirmed Monday night in a press conference near the scene — which was near mile marker 225 on I-95 South — that the man, who will remain unidentified pending notification of relatives, died around 8:15 p.m.

Police had surrounded the truck, where a man was holding a gun to his head, according to McCausland.

Maine State Police Lt. Christopher Coleman confirmed that the man had a .30-30 rifle and was in the passenger seat of the truck driven by an unidentified woman, who is unharmed and cooperating with authorities.

The woman got out of the truck shortly after it was stopped in the breakdown lane on I-95 South at approximately 4:05 p.m.

“Police were on the lookout for a U-Haul truck connected with an ongoing investigation, the details of which I am not going to get into this evening, and that truck was located near the Lincoln exit,” McCausland said. “It is the same vehicle.

“There was a woman inside who left the truck and has now been questioned by deputies and state police. She has not been charged with anything.”

Coleman and Lt. Wesley Hussey said I-95 South, which was closed to public traffic since 4:35 p.m., would remain closed for a few more hours as police continue investigating the incident. They would not confirm that the man shot himself, but said he was not shot by any law enforcement officials.

Coleman and Hussey said the man and the female driver were traveling on the interstate after leaving a hotel room at the River’s Edge Motel and Pizza Shop in Medway earlier Monday.

Police closed both the northbound and southbound lanes of I-95 between the Howland and Lincoln exits at 4:35 p.m. Traffic was detoured to Route 116 and Route 2.

I-95 North was reopened at 7:45 p.m.

State police troopers attempted to negotiate with the man for four hours.

“We’re still trying to get our arms wrapped around this incident and investigation,” McCausland said. “I suspect there will be more information released tomorrow as our investigation continues through the night and into tomorrow.”

BDN reporter Nick Sambides contributed to this report.