What would be a good punishment for a school bully ages 12 and over?

Bostonbutterfly

Bullying has obviously gotten worse by now. There were cases of the bullied victim either committing suicide or hurting the bully.

Obviously a child ages 12 and above isn't going to listen to a full lecture on treating people how you would like getting treated nor be sincere in their apology if they're send to the principal's office and made to shake hands and apologize to each other, lol. They're going to go back to bullying others or be subtle about it, only apologizing if caught but really learning nothing.

I'm not proud of this but I once punched a bully when I was 14, drawing blood. There was no ''say sorry'' nor making peace. Both of us got suspended. We just never spoke to each other since. But seriously what would be a good (effective) punishment for an older school bully that age? They're aren't actually little kids anymore and were sure having a good laughing bullying others.

Updates
7 mo
What would really make an older child like that actually change, make an impact on him/her to show that bullying is awful?'
What would be a good punishment for a school bully ages 12 and over?
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