If you think there is a chance your dog is stolen please contact the police to fill out a report. Reports are great to have on file in the chance that you find someone who has your dog and won’t give it back. Make sure that you have photos of as many angles as possible of your dogs as they also help in proving ownership. If your pet is microchipped this is THE BEST proof of ownership you can have. If you see someone with your dog the best thing to do is call the police and provide them with any evidence you can (picture, license plate, address) so that they can handle the situation.