What movie could this be?

I don't really remember much about the movie, but I remember when I was little (late 90s early 2000s) there was this movie my parents were watching where this red haired teenage liked this guy, but the guy was with this blonde haired girl and the guy and the blonde haired girl murdered the red haired girl. I don't have a clue of what the name of it is or anything else. It really bugs me when I know the movie is out there but I cannot watch it because I don't remember the name. If you have any idea of what it might be or anything please tell me. Thank you :)