Stupid question, but...

I remember seeing a movie a couple of years back (maybe 4) that looked as though it were made pretty resently, about a group of young actors stalked by a killer dressed in ,I think, a clown costume. The first one to die is a middle aged drama teacher. I also recall the killer being a middle aged male actor that had seomething to do with the lead female, who survives. The cast was small and it was an American movie, I think. So, was I mistaken in a few details and the movie I saw was this, or can anyone possibly inform me of the actual movie in question (I really want to see it again!)?