Hi,

I don't know a lot about crack but I saw your post and you seem upset so I thought i'd reply. When did he go to jail for it? Was it some time ago and has he improved since? If he was using crack I'd say you would notice a lot of changes. I'm just going by what other party drugs do to you. Change of appearance, losing weight.
If he's done it a couple of times like once a yr i wouldn't worry all too much but if he's done it in a short period of time then i would worry. I really hope someone else replies for you with some more useful information that understands this addiction better.

Harmony1xo