I have been successful so far at not having to set cage traps in attics, especially for raccoons. I have taken the extra step of putting hardware cloth around all my older cage traps to prevent them from tearing up anything within reach and most of the time I still put a piece of plywood down on a deck or roof.It protects the customers property, the animal and me from liability.
I will NOT set a body grip anywhere there is a chance for catching some bodies pet or "favorite feral cat" by accident. I've seen too many cats walking around on roofs of houses.
I can't understand the thinking process of any customer I have ever had that would tell me its ok to leave an animal in a trap in their attic till the next day. One I would never ask or suggest it because It just ain't right. Two, I have trapped long enough to have seen what animals can do in traps when they are caught and are not in attics! It's amazing what they can tear up if given the chance. And Three, I think to much of my reputation, the animal and my license to even consider that.
I may be old school, but if my customer calls at three AM and says I just heard a awful racket on the roof or porch, I carry my self over there to see what is going on and if the target animal is trapped, I remove it then. The customer sleeps better and is satisfied and will remember that when they tell their friends that I came out and took care of the problem even at three am.
I can sleep better knowing I did the right thing.