Since a driver license has the owner's address on it, it may be tempting to do a good deed and mail a found license to the owner. However, there are reasons why giving the license to police is a better idea.
State Lost License Regulations
When a person loses his driver's license, he must appear in person at the state Department of Motor Vehicles to get a new one and pay a fee. As it is illegal to drive without a license, most people will have replaced a lost driver's license within a few days of noticing its loss.
State License Theft Regulations
Some states, such as Texas, require a person who has had her license stolen or used for fraud to report the theft to the police. A license that you have found may not simply be lost but may have been stolen and used for criminal purposes.
Handing Licenses in to Police
The best action is to take a found driver's license to your local police station. The police can find the owner for you and also ensure that the license has not been used for criminal ends.