Maine police say a 29-year-old man riding in a car with his mother shot and killed her while she driving, and then opened fire on vehicles that were traveling along a busy road in Sabattus on Wednesday, killing one driver and injuring two others.

James Davis III shot and killed himself after the shootings, according to Maine State Police. The incident happened by the intersection of King Road and Route 9 near the Lisbon town line at about 4:15 p.m. 

"That's a busy area, busy time of day," State Police Col. William Ross said.

Victims identified in Sabattus, Maine shooting

Three passing drivers on Route 9 were hit by gunfire from an AK-47 rifle, police said. Katherine Williams, a 53-year-old from Sabattus, crashed into a house after her SUV was hit by several bullets. She was pronounced dead at the hospital. 

A 19-year-old and a 35-year-old driving separate pickup trucks were also shot, but were expected to survive. Police do not believe Davis had any prior connection to the passing drivers they say he shot. 

Williams, who went by Kay, was the kitchen manager at two schools in Litchfield, where she had a remarkable ability to build strong connections with students and staff, Superintendent Katherine Grondin said in an email.

"Her kindness and dedication made a lasting impact on our school community, and she will be deeply missed," Grondin said. "Our hearts go out to her family as they navigate this loss. It has been a difficult day for all of us as we mourn the passing of a valued and beloved member of our school family."

Davis was living with his mother, 47-year-old Christine Smith, in Sabattus. Police said he was in the passenger seat when he shot her with a revolver as they were driving, and then got out of the car with the rifle in hand.

"He pointed it down the roadway to oncoming traffic that was traveling from Lisbon into Sabattus on Route 9," Ross said.

Family said Maine shooter was acting erratically

Police said family members that saw Davis earlier in the day noticed that he "started to act erratically and say things that didn't make sense." But they did not indicate that he had a history of mental health issues, Ross said.

State police and Lisbon police said they do not have any record of encountering Davis before Wednesday.

Investigators are working to learn more about the guns Davis had. Police believe he had one or two more guns with him on Wednesday, in addition to the revolver and rifle.

"He had a lot of firearms, and he had firearms back at his house as well," Ross said.