DETROIT (AP) — A prosecutor announced murder charges Wednesday against a 34-year-old man in the slayings of four women in Detroit whose deaths authorities have characterized as the work of a serial killer.

Deangelo Martin is charged with four counts of first-degree murder and four counts of felony murder in the killings of the women whose bodies were found in abandoned houses in the city as far back as February 2018, Wayne County Prosecutor Kym Worthy said at a news conference.

Martin was arraigned Wednesday afternoon.

Martin, who was arrested in June, was already charged in the stabbing and sexual assault of 26-year-old woman in May and the kidnapping and assault of a 51-year-old woman in June.

Police Chief James Craig has said he sees similarities between three of the slayings and the assaults of at least two other women who survived attacks.

“I think it’s pretty clear that we believe he is a serial killer,” Worthy said.

She named the victims as Annetta Nelson, 57, whose body was found Feb. 26, 2018; Nancy Harrison, 52, who was discovered March 19, 2019; Trevesene Ellis, 55, was found March 24; and Tamara Jones, 55, who was found June 5.

A coroner determined that Nelson and Harrison died of blunt force trauma but the cause of death for the other two couldn’t be determined because their bodies were too badly decomposed.

Police have said they believe all the women were sex workers.

“Predators … look for people who are seemingly vulnerable, left out and left behind,” Worthy said. “People that they think will not fight back, people that they think nobody cares about, people that they think won’t be missed. But they’re wrong.”