hmm...I think I have a different theory on the killer, and how Kenny was found before his murder.
So, Kenny liked to spy on the ladies, right? That would be a good reason for a female to kill him, but the only females left are me, and Jeanine, and neither of us would have a strong reason to have killed Kenny, which means it could still be somebody male.
This male killer happened to spot Kenny climbing into the vent, and they asked why he was doing that.
Kenny replied with, "I'm spying on the girls, what's it look like?"
This made the killer FURIOUS. They screamed to him, "YOU PERVERT! DON'T DO THAT!"
That person then grabbed Kenny and smashed his eye onto the bathroom door handle, until he was dead.