FRESNO, Calif. >> A good Samaritan who came to the aid of a woman being assaulted by twin brothers was brutally beaten by the suspects before being run over by a driver, police said.

Nathan Halsted, 49, died in the early Monday morning incident. At a news conference on Thursday, Fresno police played video from a department surveillance camera that shows Halsted being punched, kicked and stomped on for several minutes before being run over. Police said Halsted was unconscious in the street, and the driver did not see him.

The two suspects, 18-year-old twin brothers Gerald and Jared Smith, fled the scene but were arrested on Wednesday on suspicion of assault and murder, police said. The boys’ mother, Lou Ann Smith, told KFSN-TV her sons were the ones who got jumped.

Police, however, said the teens attacked Halsted after he came across them assaulting a 35-year-old woman at a gas station while riding his bike and told them to leave her alone. The brothers also fought a driver and pedestrian who tried to intervene in the attack on Halsted, police said.

“Like an animal pursuing prey, and that’s what they were,” Fresno Police Chief Jerry Dyer said. “If one person walked by, they went after them.”

Lou Ann Smith said her boys did not run over Halsted, so the driver should be the one arrested on suspicion of murder.

Dyer disagreed, saying the driver, who was on his way to work, was despondent after hitting Halsted and was not at fault.

“The people that are responsible for this are Jared and Gerald Smith, who are the ones that unnecessarily beat this victim, left him in the roadway, ultimately allowed him to be run over by a vehicle and killed,” he said.