[From the T2A Strategy Guide] "Trapped Boxes"

[Cutpurse]

If you trap a chest in a building or boat that you own (that is, you have the key to that building or boat in your backpack while working in the building or on the boat), you will not be flagged a criminal or murderer for anybody harmed when the trap goes off, even if you take the chest out of your building or the boat later. The chest has to be on the floor of the building or on the deck of the boat when it's trapped, not in your inventory or even on furniture. If you trap a chest anywhere else (including non-movable monster and NPC chests) you will be held criminally responsible for anybody harmed by the trap.

Not sure if this was changed later o, but it is interesting for tinkers who don't want to go red.

[Faust]

This works fine with houses... However, this may not work for a boat that you own though. I can't really comment on that scenario.