Detectives and crime scene investigators spent much of the day combing the Cary apartment for evidence of the hours-long assault.
Late Tuesday evening, authorities identified the suspect as 34-year-old Adrain Shawn Atwater.
Detectives have an arrest warrant for Atwater charging him with second degree sex offense kidnapping and felony strangulation.
Police say they don't believe Atwater is an immediate threat to the public because, they say, he knew the man he attacked and that the victim invited Atwater into his apartment.
Authorities say the man who lives in the apartment called to report the crime around 9:30 a.m.
"He advised us he was held against his will and sexually assaulted from about 1 a.m. this morning until he was able to get away and report it," Cary Police Department Capt. Don Hamilton said.
Hamilton says when Atwater went to the bathroom; the victim bolted and ran for the office at the Merriwood Apartments.
The victim was taken to the hospital to be treated for injuries and so that doctors could also collect evidence for investigators.
Neighbor Chelsea Briggs says she came home to the crime scene Tuesday and was shocked when she found out what happened. She says she is always on guard for rapists.
"I keep my door locked, always keep a can of pepper spray in my pocket, you know, I got a taser," she said.
Briggs also says she can't believe a man was sexually assaulted by another man.
"That's very unusual," she said. "I don't think it's right to bring that on anybody if they don't want it. But I think a man can be victimized just as much as a woman."