Many hospitals offer free x-raying for treats as a community service. If you are really concerned about tampering, check in your local area to see if this service is available. If you are driving on Halloween - exercise extreme care. The children are excited, many are wearing dark clothing, and most have been known to run into the street without watching for traffic. Don't limit your caution to residential neighborhoods.
Busy thoroughfares are just as hazardous.
Party revelers and teenagers may be out on these streets. An extra few minutes to slow down and actively look for hazards is far better than a few hours spent with the police or a lifetime of regret over hitting someone or something. This is the single most important rule that you can remember on this night when the dead are supposed to walk the land. You don't want to be among them. Decide on a designated driver before you arrive at your destination or decide to take a taxi.