Many police vehicles have computers now known as mobile data terminals (MDTs). These laptop sized computers permit the officer to perform rapid searches of law enforcement databases. In addition to information concerning active criminal and traffic warrants, the MDT also provides basic information about motorists. By typing in the license plate number, the MDT provides information concerning vehicle registration and whether the owner of the vehicle is legally licensed to drive in New Jersey.
The question arises whether a MDT report of a problem with the vehicle registration or the owner’s driver’s license constitutes a sufficient legal justification to effect a motor vehicle stop. The New Jersey Supreme Court answered this question in State v. Donis, 157 N.J. 44 (1998). The court held that motorists have no expectation of privacy in their license plates or associated numbers. The plates are always located on the outside of the vehicle and must be easily viewable. On the other hand, there is an expectation of privacy with regard to information associated with the license plate number. Data such as the home address, social security number, and name of the owner of the vehicle are protected by both state and federal law.
In order to balance these competing interests, the New Jersey Supreme Court in Donis created a two step process to be performed by law enforcement. Police are permitted to randomly enter license plates numbers into the MDT. The system will report back basic information regarding the registration status of the vehicle, the driver’s license status of the owner, and whether the vehicle has been reported lost or stolen. Other personal information about the owner may not be displayed in the first step. If the data received during the first step warrants further investigation (because the vehicle is not registered or the owner’s license is suspended), the police are permitted to access personal information through the MDT. This may include the owner’s name and address, social security number, and criminal record. The Supreme Court has ordered that when the police do not receive evidence of problems with the vehicle or the driver, they may not proceed to step two and access personal information.