We would trap them in cardboard boxes and drive them a mile up the road and let them out in the woods. Our mouse issues persisted and my dad and I kept telling her that the same mice kept coming back, but she didn't believe us. We finally convinced her to drop nail polish on top of them while in the box and then let them go even further away, which she assented to. Next time we caught a mouse it had nail polish on its back. She was ok killing them from then on.