Something about this makes me feel really uncomfortable. I do find it interesting and can understand why you‘ve tried it out but, in all honesty, I couldn’t think of it getting very far before coming back to their crime/their innocence if that makes sense? I think it’s that sense of it being very one sided, e.g. you only really know what they’re telling you. if it then came out that the person I was writing to was a murderer or rapist, I don’t think I could live knowing I’d supported them and would worry if they had my details (address, phone number etc) or if they became manipulative toward me. I dont think I’d mind as much if i was using temporary details, like a burner phone or fake email type thing.
I also think that some people who use prisoners as pen pals - not you, but generally - think they’re ‘saviours’, that they can save and rehabilitate someone, that they’re doing something ‘good’, especially if the messages they receive in return are manipulative ‘I’m innocent’ type, and that’s why talking to prisoners has become so popular recently in comparison to, idk, making friends through a forum or sending letters to the elderly. Again this isn’t specifically towards you I’m just musing out loud.