honestly this is one of the best movies I've ever seen I've never been so confused then so sad then so understanding in my whole life, if u guys didn't know from the end of the movie all of the killers family where dead and the cat was the last thing he had for a family and watching it die pushed him over the breaking point and he went physco to try to save his only loved one left for all u surface level watchers that was the plot of the movie and what the storytelling was trying to show.