The National Highway Traffic Safety Administration (NHTSA) has developed determinants for drunk driving detection, which police officers may use to determine if a driver is drunk. These determinants should be followed in a three-stage process: observation of the vehicle while in motion, how the driver behaves once the vehicle is stopped, and the driver's performance on field sobriety tests. A DWI attorney in DC can use these determinants to determine if the police had probable cause to stop the driver and potentially have the charges dismissed.