[Icemaster]

Assuming you're staying in the realm of what you're legally allowed to ask...

Character questions that are open ended. Get him into a conversation around principles, how he handles conflicts, situational questions i.e. when he brings up a situation or event, look for the opportunity to ask if he'd do anything differently the second time around. See if he's learning.

I'd want to try to find out where he draws his lines on behaviors and what's most important to him personally, that might give you a view into motivations and how far he's willing to bend/break rules or laws to get them.

Biggest thing is to make it conversational and get him talking as much as possible, people never cease to amaze me with how much they'll tell you with the tiniest bit of encouragement. From there, trust your gut.