I mean if it were purely up to me I would be perfectly ok with a lethal bait box but if I did manage to harm somebody I could be held liable. We have had several cases where someone broke into someone's house, managed to injure themselves and successfully sued the homeowner, ridiculous but it happens.
Anyway this first time around I just want to try to lure them into having their license plate captured as they pass by. If they snag this box then there's a pretty good chance they live nearby and will swipe other boxes. At that point if I have not caught them I can try a dye pack, spraypaint can with a mechanism to puncture it, shotgun blank (LOUD!!), smoke flare, tracker or some combination of things. Once I hit someone with that though they'll know they've been baited and that particular person likely won't give me another opportunity to get them. The possibility of retaliation is a concern too.