I got a question about a movie need to know the ending?

I forget what the name of the movie is called but it has Bruce Willis, Sarah Jessica Parker and Tom sizemore. Willis is a patrol officer who is trying to figure out who murdered girls he use to date. I got to almost the end and had to head somewhere. How does the movie end? Is Sizmore the guy who is killing all the girls? It was one of his first roles and he usually plays seedy charters. Thanks for your help!