Nathan Allen, 28, stole a truck from a plumbing company, crashed it into a home in Winthrop, Massachusetts, then got out and killed bystanders David Green and Ramona Cooper, said Suffolk County District Attorney Rachel Rollins. Police who responded to the scene fired on Allen, who died in hospital.

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

“This individual wrote about the superiority of the white race. About whites being ‘apex predators,'” Rollins added. “He walked by several other people that were not black, they are alive, they were not harmed.”

Police described the victim Green as a retired state trooper who had served 36 years on the force, while Cooper was identified as a 60-year-old Air Force veteran. Cooper died in hospital after being shot three times in the back. Green was shot four times in the head and three times in the torso, and pronounced dead at the scene.

In security camera footage obtained by ABC News, the stolen truck can be seen being driven out of frame, after which a loud noise is heard, described as the sound of it hitting the house.

White supremacist propaganda in the US, including racist, anti-Semitic and anti-LGBTQ messages nearly doubled last year to a record level, the Anti-Defamation League said in March. The New York-based advocacy group’s data showed 5,125 cases reported in 2020, compared to 2,724 in 2019.