A customer of mine was arrested for felony animal abuse. How do I turn down doing any service for him?

I own a repair shop and had a young teen customer come in who was a bit of a pain but paid the same and we got the job done.

A few months ago, I saw on the news he was arrested for shooting a dog and dragging it behind his motorcycle for a few miles to bury it. I was disgusted when I saw that and was hoping to never see him again. Unfortunately he just called to come in the other day and I didn’t realize it was him until the end of the phone call when I got his name.

I do not want to work on his bike and frankly don’t want to see him and I’m not sure how to react if he decides to come in. I obviously will be professional but he’s a bit of a loose cannon (obviously). Normally I don’t care about people’s past but I don’t want to work on a bike that dragged a dead dog by a psycho.

What should I do and how should I reject him?