Chainsaw murderer

Last night I dreamt I was trying to investigate a serial killer who enjoyed decapitating people with a chainsaw. He was sitting on the stairs next to the headless body of his most recent victim. I was coming up behind him with an officer and my sister when these guys started being extremely rude to her and so I told them off. The serial killer heard the commotion and realized we were coming for him, started his chainsaw, grabbed his first hostage and sliced her from shoulder to shoulder and I watched her top half slide off onto the ground. Then he came at us.