then i was befuddled myself. >> reporter: o'shea says they met regularly after that.n he got out, she introduced him to her landlord who, with perry's blessing, invited o'shea to move into the building. today they don't just live close, they are close. clearly mary was able to forgi forgive. >> unforgiveness is like cancer. it will eat you from the inside out. it's not about that other person. me forgiving him does not diminish what he's done. yes, he murdered my son. but the forgiveness is for me. it's for me. >> reporter: for o'shea, it hasn't been that easy. >> i haven't totally forgiven myself let yet, i'm learning how to forgive myself and i'm still going towards trying to forgive myself for what it is i've done. >> reporter: to that end, o'shea is now busy proving himself to himself. he works at a recycling plant by day and goes to college by night. he says he's determined to pay back mary's clemency by contributing to society. in fact, he's already working on it, singing the praises of god and forgiveness at prisons, churches, to large audiences everywhere. >>