Authorities identified Shirellda Terry, an 18-year-old praise dancer and home-schooler, as the third victim on Wednesday, according to the Cleveland Plain Dealer. She was last seen leaving her summer job on July 10.
Police had previously identified Angela Deskins, 38, and Shetisha Sheeley, 28, as the other two victims.
Sheeley's family had already been rocked by tragedy this year, when her brother, Don'tel, was shot to death last December.
"Three individuals who were minding their own business were killed senselessly by an individual with no regard for human life," Mayor Gary Norton said at a news conference on Monday. "As a community we are dealing with the tragedy, we are healing and we are strong."
"We feel there may be more to this. This is an ongoing investigation. We're nowhere near done," East Cleveland Police Chief Ralph Spotts added.
Michael Madison, a 35-year-old registered sex offender who spent four years in prison for attempted rape, was arrested Sunday in connection with the murders. He reportedly told investigators that Anthony Powell, who murdered 11 women from 2007 to 2009, had "influenced" him.
Madison now faces charges of aggravated murder and kidnapping.