A spokeswoman for the Wayne County prosecutor said Saturday that the case remains under investigation and no charges have been filed.
Police say the homeless man was taken into custody Friday night, two days after the body of a woman was found in a vacant house on Detroit's east side. The bodies of the other two women were discovered in separate empty dwellings earlier this year. Investigators believe the deaths are related.
"We believe this is a serial murderer and rapist, and we want to alert all sex workers — particularly those who work inside vacant houses — to beware," Detroit Police Chief James Craig said last week, before the man was taken into custody.
Police have not described the man as a suspect. The Detroit Detention Center confirmed Saturday that he was still in custody, but declined further comment.
A message seeking comment was left with a police department spokesman.