Elephant (2003)
Elephant is a 2003 drama film edited, written and directed by Gus Van Sant. It takes place in the fictional Watt High School, in the suburbs of Portland, Oregon, and chronicles the events surrounding a school shooting, based in part on the 1999 Columbine High School massacre. The film begins a short time before the shooting occurs, following the lives of several characters both in and out of school, who are unaware of what is about to unfold. The film stars mostly new or non-professional actors, including John Robinson, Alex Frost, and Eric Deulen.
More at Wikipedia.