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How do police spot drunk drivers?

On Behalf of | Jul 30, 2024 | Criminal Defense

Some DUI stops begin as minor issues. Perhaps a person’s license plate light has burned out, so an officer pulls them over to let them know. The officer then realizes that the driver is impaired and makes an arrest.

But these cases can sometimes be problematic for the prosecution, as the defense can argue that there wasn’t really probable cause. The driver didn’t make any mistakes or put anyone in danger. They were just pulled over on a technicality and now a DUI charge would change their life forever. As such, police will often look for more concrete reasons to make a stop, watching for clear indicators that the driver is impaired behind the wheel.

Signs they look for regarding impaired driving

Although signs of impairment can take many forms, here are some of the most common ones that police officers look for:

  • Someone who is driving at night but doesn’t have their headlights on. 
  • A car that keeps drifting between lanes or drifting over the centerline and into oncoming traffic. 
  • A driver who has a near miss, such as almost driving off of the road or almost hitting a parked car. 
  • Someone who is driving erratically and unpredictably. 
  • Someone who is speeding or even driving far below the posted speed limit. 
  • Drivers who don’t react as expected to the road conditions, such as a driver who stops well in front of a red light or who does not proceed forward when that light turns green. 

The probable cause for the traffic stop is just the first step. Officers will often then collect other evidence, such as the results of a breath test or a field sobriety test. Those who are facing serious criminal charges in Arizona need to know all of the defense options at their disposal.