The tabloids have a field day with wayward ambassadors who claim immunity when they get nabbed for reckless driving. These stories hit the headlines and reinforce the public misperception that diplomatic immunity is a "get-out-of-jail-free" card for breaking the law overseas. In reality, diplomatic immunity exists to smooth foreign relations between countries. It doesn't give anyone a license to defy the law.
So, what are the benefits of diplomatic immunity?
Diplomatic immunity protects the location of a diplomatic mission from search. Diplomatic personnel are immune from criminal prosecution as well as most civil suits in the host country. However, those protected are still required "to respect the laws and regulations of the receiving state." To repeat, diplomatic immunity isn't the "get-out-of-jail-free" card it's perceived as. The home country can revoke a diplomat's immunity and allow the host country to prosecute. Most countries are reluctant to take this step. Diplomats typically face sanctions at home. The host country can also force the home country to recall someone immediately.
Usually, diplomatic officers commit what we call garden-variety offenses. Petty theft and traffic violations are near the top of the offense list. A study from the 1980's showed that diplomatic immunity was claimed 147 times in six years in the WashingtonD.C. and Manhattan area. And the most common offense? Shoplifting! Apparently, "sticky fingers" is the top crime among those with immunity.
The most serious abuses of diplomatic immunity come out of debt recovery, not petty crime. Depending on the type of transaction, a creditor can be helplessly stuck with pretty steep bills. Bank accounts of the embassy and embassy personnel are protected under diplomatic immunity. This creates countless problems for creditors and law enforcement.
Still, you're more likely to be hit by a truck than assaulted by an overseas diplomat. Worrying that the truck driver will turn out to be a Russian ambassador who is entitled to immunity is a story best left to Hollywood