Considering the death location was in the closet kitchen and because of the female scream, White could have ran to the kitchen and then atacked her in the Kitchen, The Killer hit White in the leg with a bat, then Dragged her in the closet the took the clever and... well... you know...the deed was done... the killer accedently left the cleaver and to be honest I never found the bat. woops.
So since it was in the kitchen and there is only one person who was in the kitchen I think its Rainbow for sure.