My guess is that LE found a resident who said he heard sounds that made him come out. I believe that I saw something--I'll look for it , that states the resident called out. No answer. He came closer yet, and called out again is what I think I read. But then when he didn't see or hear anything, he returned to his apartment. The timing and times given by everyone probably got LE thinking that JM heard the person, and decided to high tail it out of there in case the person was calling LE or getting others to come check out the sounds. But whether that is the case or not, we don't know.
The victim passed out so she has no idea what made JM leave when he did.
The rape is likely to be a slam dunk conviction. Attempted murder would depend on the seriousness of the injury and the opinions of MDs as to whether it supports that charge. There was a similar case in the courts around here, and the court did not get the attempted murder part of the charge through as it could not be proven that the injuries were such that the perp was trying to kill the woman. That he could have killed her but stopped way short was instrumental in getting those charges a not guilty verdict in that case in my area.
I'm interested in knowing whether the victim will come testify. In such cases, DA and defense often play "chicken" with DA holding the stance that the victim is definitley going to show up even if it's uncertain or if she has said she would not, and the defense hoping that at the last minute the victim demurs . If the defendent does not show, the case could fold, so DA would want to strike a deal with that as an uncertainty so that the terms would be as tough as possible Defense would have the opposite objective.