You have to keep in mind that most of these smugglers won’t be nice. There are even times when a superior will warn you about a particularly suspicious vehicle. When things get out of hand, you can always request backup.
You’re not completely on your own though because you will have the support of your comrades and superiors. As the post inspector in Contraband Police, you serve as the first line of defense against gangs who will try to infiltrate your base with illegal drugs, weapons, and even cash.