A suspected serial killer who Detroit police believe preyed on women on the city's east side has been charged with four murders, Wayne County Prosecutor Kym Worthy said Wednesday.

Deangelo Martin, who already has been charged in two nonfatal attacks on women, was arraigned Wednesday afternoon in 36th District Court on eight counts related to the slayings of four women.

Martin, 34, 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.

"We are confident that this defendant's alleged criminal and predatory actions link him to all four of these homicides, as well as the two sexual assault cases that we charged him with previously," Worthy said.

Martin was arrested in June and 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.

Worthy, who was joined at a news conference by investigators from her office and Detroit Police Chief James Craig,identified the victims as Annetta Nelson, 57; Nancy Harrison, 52; Trevesene Ellis, 55; and Tamara Jones, 55. Police said earlier that Jones’ badly decomposed body was found June 5, Ellis was discovered May 24, and Harrison was found March 19.

"When you look at the victims in terms of their age ... we know the suspect focused on a certain demographic," Craig said.

After police arrested Martin in June, Mayor Mike Duggan said police and other city employees would search and board up abandoned structures in Detroit, with a goal of having them all boarded up by the end of September.

Detroit police deputy chief Todd Bettison said Wednesday that 4,207 houses had been searched and secured as of Tuesday. He added the crews are on schedule to have the job finished by the end of the month, as originally planned.

Martin was impassive and answered that he understood the charges as he was arraigned via video.

A plea of not guilty was entered on Martin's behalf. He was not given bond and remanded back to the Wayne County Jail. He was scheduled for a probable cause conference Oct. 2 and a preliminary examination Oct. 9.

"You are a danger to the community," 36th District Court Magistrate Laura Echartea told Martin.

"This is the kind of case that creates so much fear in our community," Craig said.

"Everywhere I went, people were talking about it," Worthy said.

She noted the "commonality" of the victims, and the fact that the women's bodies were found in a kneeling position and that used condoms were found nearby. The victims were mostly found in the same area of Detroit, said Worthy.

"We believe he's a serial killer," she said. "What's most important is that Mr. Martin is brought to justice."

Worthy said her office and police are looking at two additional murders to which Martin "might" be connected.

"So this may not be over," she said.

George Hunter contributed.