How can I handle this horrible incident at school?

As if it hasn’t been stated previously, I am in my last year at high school, thank you Jesus. Most of the time now I can let comments and nasty people roll off my back because they are not friends or people who are reliable. Case in point, I was walking down the hallway and that’s always mobbed. This asshole running by with a book bag ran right in front of me after colliding with me and slapped me across the face. He ran away. I don’t know a lot of these people, so I have no name to go on which sucks. I don’t know if I should report it or just pretend it never happened. But I’m upset. Certain people don’t like actually having to do a job and sweep things under the rug. I fear that if I do report it, they won’t be able to do anything because stuff like this has happened before and nothing got resolved. I had another incident in which someone attempted to push me down the stairs.
I did say something but I doubt they checked any security video. Am I doomed then? It’s rare that I do have a witness.