Stop and take a deep breath here and know that you don't have to do anything. Doing nothing is an action if it is a choice we make.
The "What If's" will get the better of you if you let them, and so will horror stories of Canadian Jails. His consequences took him there and he'll learn better just left on his own.
If you don't want anything to do with him, or want to keep him away from the children (which isn't a bad idea when someone is in active addiction), then maybe get a restraining order for when he gets out.
For the sake of your children, you may want to think about your own future and how peaceful it could be without all this chaos and crime.
Whatever you choose, we're walking with you here. Prayers for you and your kids.
Hugs