The police is after Warren because he was involved in Reena Virk’s murder. He helped killing the girl. It was prom day and he promised to take you to dance but he called saying that it wouldn’t be possible because he was staying at Rebecca’s, he knew you got so disappointed by this and decided to go to the prom just to see you for the last time and say goodbye because he knew it was gonna be the last time he would be able to see his girlfriend.