When an officer performs a routine traffic stop, they must have reasonable suspicion to believe that the driver of the vehicle was breaking the law. However, to arrest a driver on suspicion of drunk driving, the officer must have probable cause to believe that the driver was driving under the influence of alcohol or drugs.
Reasonable suspicion vs. probable cause
The Fourth Amendment of the U.S. Constitution protects drivers from being subjected to an illegal search and seizure. In other words, if a Farmington Hills officer arrests a driver without probable cause, the arrest is considered unlawful and charges may dropped against the driver. While both reasonable suspicion and probable cause are both based on the officer’s reasonable belief of a crime, probable cause is based on hard evidence and facts available to the officer.
Establishing probable cause
Police officers must establish probable cause with the following evidence:
- Personal observations – The officer may have smelled alcohol on the driver’s breath or in the vehicle or may have noticed the driver’s slurred speech or bloodshot eyes. These observations may be used to show the driver was driving under the influence.
- Field sobriety tests – The officer may ask the driver to submit to various tests including the walk-and-turn, one-leg stand, and horizontal gaze nystagmus (HGN).
- Chemical test results – The officer may ask the driver to submit to a Breathalyzer or chemical test to establish the driver’s blood alcohol concentration.
Drunk driving charges are serious, and you will require a solid defense strategy to defend against these charges.