<human>: Summarize the given text in a few sentences.

We are in highschool by the way.

Friends fake name is Jim

So I was in gym today when Jim walked in with a short sleeve shirt. He had been wearing a jacket all day so no one had noticed the marks on him.

Well, me and my buddy walked up to Jim and asked him what happened out of curiosity. The marks are 4 deep, red, scabbed over (what look like claw marks) on his arm. 

His response was "his mom scratched me. She can be a bitch" It didn't seem like he was joking and when my buddy asked what he did to make her react violently he just stopped talking and ignored us.

Look this could be a misplaced joke. But if his mom actually physically hurt him, I would want to tell someone. This has been on my mind all day and I don't know if I should speak to a teacher or act like it was a joke.

Now Jim is a troubled kid so It wouldn't be the most shocking thing if his parents were a bad influence on him.  And a teacher recently made it clear that he's had to call CPS on 2 kids before. Both cases turned out to be forms of abuse. And that if we see anything to speak up.

Again, maybe this was a bad attempt at a joke. But I don't really know what I should do. Maybe his mom was defending herself, but I've never known Jim to be violent, he just smokes weed.
<bot>: My friend came into gym with cuts on his arms and claimed his mother did it. Don't know if I should tell a teacher?