A man allegedly rammed a stolen truck into a house before fatally shooting a retired Black Massachusetts state trooper and a Black Air Force veteran Saturday, according to police. Authorities said they are investigating the incident as a hate crime.

The suspect was later killed by police when they tried to apprehend him, investigators said.

David L. Green, a 36-year veteran of the force, and Ramona Cooper, 60, lived in Winthrop, Massachusetts, where Saturday afternoon’s incident took place, police said.

Around 2:45 p.m., the suspect, identified by police Sunday as 28-year-old Nathan Allen, allegedly drove a stolen box truck into a home, but there was no one at the house at the time, police said.

Winthrop Police Chief Terence Delehanty told reporters when officers arrived at the scene, they found one victim shot half a block away.

The second victim “engaged with the suspect” in an alleyway not too far from the crash and was shot, Delehanty said.

Cooper was shot three times in the back and Green was shot four times in the head and three times in the torso, Suffolk County District Attorney Rachael Rollins said in a press briefing Sunday.

Green died at the scene while Cooper was pronounced dead at the hospital, police said.

Officers fired at Allen, who was struck and later died at the hospital, police said. One officer was struck by a bullet but wasn’t seriously injured, Delehanty said.

Rollins said Allen had “troubling white supremacist rhetoric found in [his] own handwriting,” and there was evidence of “anti-Semitic and racist statements against Black individuals.”

“This individual wrote about the superiority of the white race. About whites being ‘apex predators,'” Rollins said. “He drew swastikas.”

Rollins said the alleged suspect was married, employed, had a Ph.D. and no criminal history, so he would appear to most as unassuming.

“And then, yesterday afternoon he stole a box truck, crashed it into another vehicle and a property, walked away from the wreckage interacting with multiple individuals and choosing only to shoot and kill the two Black people he encountered,” Rollins said in a statement Sunday night.

Rollins said Allen had a lawful license to carry that transferred from another town. The investigation is ongoing.

Colonel Christopher Mason of the Massachusetts State Police said Green joined the Metropolitan District Commission Police in 1980. According to Mason, he became a Massachusetts State Trooper in 1992 when the MDC Police merged into the state police and served for another 14 years before retiring.

“Trooper Green was widely respected and well-liked by his fellow Troopers, several of whom yesterday described him as a ‘true gentleman’ and always courteous to the public and meticulous in his duties,” Mason said in a statement.

“From what we learned yesterday, he was held in equally high regard by his neighbors and friends in Winthrop,” Mason said.