Is there anyone you’ve personally known who went to jail/prison and was a better person after being released?

Yes. One. She was a good person before prison. And more so afterwards. 

I know another who did not change at all. 

I have only known one person who had been jailed...my brother. He was a good person already, but spent much of his adult life drinking and drugging and in and out of jail. He never changed and died about five years ago.

My father and he came out better...................sort of.

I don't think I do.