A driver’s license is a privilege, but as a motorist you also have a certain set of rights. For instance, police need a reason to pull you over.

Every traffic stop, including stops for drunk driving, must begin with reasonable suspicion. Police officers must think that a law is being violated before they can make the stop. The basis for reasonable suspicion varies widely – from traffic violations to a malfunctioning tail light – but it is always important to know your rights.

“More than a hunch”

A police officer cannot pull you over on a whim. The New Hampshire Supreme Court ruled in 2014 that, “Reasonable suspicion must be more than a hunch, and the articulated facts must lead somewhere specific, not just to a general sense that this is probably a bad person who may have committed some kind of crime.”

In short, if a cop doesn’t have a valid reason for issuing the traffic stop, it may be illegal, unconstitutional and inadmissible in court.

What constitutes reasonable suspicion?

Police officers are trained to identify many different signs of impaired driving that constitute reasonable suspicion. Those signs include:

  • Swerving
  • Failure to turn on headlights
  • Crossing the center line
  • Drifting or weaving between lanes
  • Illegal turns
  • Slow driving
  • Braking frequently
  • Driving with face close to the windshield

The above are just a few examples. There are many different actions that amount to reasonable suspicions, and they do not necessarily need to suggest drunk driving. A police officer could pull you over for any driving violation, and if he or she suspects you’ve been drinking he or she can ask for a sobriety test.

Reasonable suspicion or probable cause?

Reasonable suspicion is different from probable cause. Reasonable suspicion requires less knowledge of wrongdoing than probable cause. A police officer has probable cause when there is evidence that a crime has likely been committed.

In a DUI stop, criteria for probable cause include failing a field sobriety test or registering a prohibited blood alcohol content on a breath test. Either of these can provide probable cause for a drunk-driving arrest.

Was there reasonable suspicion?

Often reasonable suspicion is a gray area. If there was not reasonable suspicion during a traffic stop that led to a DUI arrest, that could be grounds to dismiss the entire case. If you’re unsure if police violated your rights, it is always smart to speak with an attorney.