Check out the instructor's credentials. Ask your local police department if they know anything about the instructor. Visit a class. Make sure the instructor teaches how to fight for defense, not for competition. You don't want to just look good on a mat.
Some people carry weapons such as guns, knives, or spray chemicals to ward off attackers.
Unless you are trained and not afraid to use these weapons, they can be very dangerous. The attacker might be able to turn them against you. Also, some weapons cannot legally be carried, so check with local law enforcement authorities. Submitting to an Attack Even with mental preparation, an assortment of personal safety devices, great skill in Judo, and a good measure of caution, you may not be able to prevent an assault. It's not always possible to escape an assault.