Live mousetrap with dead mouse

The mousetrap was supposed to catch the mice alive in our garage, but after I had the case at night stocked with something Keksgrümmeln, was the next morning actually a mouse in it. Problem is, the mouse has stopped in its panic the plastic lever to trigger and slashed in agony at the cutting edge thus incurred his stomach. The mouse had died in agony and I had 2 weeping toddlers who actually wanted to expose their living mouse in the field ........ so I can not recommend the case absolutely