“ Despite all this, the two survivors don’t check out anything further until the (late) morning at which time they discover evidence of the crime and call in friends and the police”
No - one of the surviving roommates (Dylan) saw the masked killer.
She thought Kaylee was playing with the dog. The dog barked. She heard cries. She heard the murder say “I’m here to help you”. He walked by her!
Idaho has a death penalty. We will see him killed by lethal injection in 2051.
Then what did she do—go back to sleep? You see a masked man n your house and peoepl crying and dogs barking at 4am.....weird.