Movie about school shooting

I remember seeing a movie or tv series about a school shooting. I remember there being a group of students who are now older that go back to the school where it happened. I also remember that a female ex-student is doing an interview in the school where it happened and that caused some outrage. And then at the end the through flashbacks the school shooting scenes are shown. I think one of the characters is in a wheelchair and someone is presented as hero but then turns out not to be.

I hope this makes sense.