Can a police officer randomly stop a vehicle and arrest someone for DWI?

• A. Yes, if the driver appears intoxicated
• B. No, you need reasonable suspicion or probable cause
• C. Only with a warrant
• D. It is allowed in some states

Answer: (B)

A police officer cannot stop a vehicle at random to arrest someone for DWI unless there is a justified reason to seize the vehicle in the first place. A traffic stop is a seizure, and under the Fourth Amendment it must be supported by reasonable suspicion that a traffic violation or some impairment is occurring. Only after a lawful stop can the officer observe signs of impairment and gather evidence—such as field sobriety tests, observations of behavior, or chemical test results—that create probable cause to arrest for DWI. If probable cause exists, the arrest can proceed without a warrant. Note that sobriety checkpoints are allowed in some places under strict rules, but they are not random stops. So the correct idea is that you need reasonable suspicion or probable cause, not a random stop.