Thank you for this--I cannot see the FB post so I did not know that.
I wonder, even though that is risky as well, if the perp stayed around for some time. Neighbors realized things quieted down and felt all was fine. He then left later casually later, maybe even cleaned up first, when no one was concerned any longer. That though too, seems unlikely, as he would have no way of knowing LE had not been called and would not be there at any second.
Not to cast any suspicion on anyone specific, but I have even wondered if it could be a neighbor (big complex--I mean any neighbor and no one specifically). That person if someone just happened to see them would perhaps not be even noticed as people are used to seeing him around and may have no idea of what apartment he lives in at a big complex like that.
A neighbor could also, if they had her number or knew her or even just where she worked, call and say your blinds are open and I know they were shut, I think someone may be in your apartment, or your cat got out, your door is open, etc. They slip back to one of the many apartments in the complex, again no one thinking much of seeing him because they have seen him around before. He then also cleans up easily and ditches his clothing in the dumpster in case LE comes questioning residents?
I don't know--nothing makes perfect sense at this time. Just thoughts.
Jmo.