Arizona's track record in terms of crime is not unlike that of other U.S. states, and property crime is a little higher than average in Phoenix and Tucson. In these big cities you should take the same precautions you would anywhere—be aware of what's going on around you, stick to well-lighted and populous areas, and quickly move away from any situation or people that might be threatening. Wherever you go, don't leave anything valuable in your car.
Check the U.S. government travel advisory before you plan a trip to the Mexico border towns. Visitors should take extra precautions.