If you look at the base of the antlers, where they were attached to the skull, and the bumb and valleys are mirror images of each other, then they are from the same deer provided there is not an injury to the pedicle. If they are not mirror images, then they are from different deer. A buck will keep this charactoristic year after year, so you can tell if you are finding the same buck's sheds year after year by looking at the attachement site. It is almost like a fingerprint.