Establishing Probable Cause for a DUI Arrest
Police enforcement of Pennsylvania laws prohibiting driving while under the influence of alcohol has resulted in a record number of arrests. The Pennsylvania State Police reported 19,518 DUI arrests by their officers last year. Stopping a vehicle and arresting its driver for DUI cannot be done unless the police officer has probable cause to believe the motorist has violated the law. An arrest made without probable cause violates the U.S. Constitution and Pennsylvania laws.
Probable cause and reasonable suspicion
Probable cause exists if a police officer has reason to believe the person about to be arrested has committed a crime. This belief must be supported by evidence available to the officer at the time of the arrest and lead to the logical inference that a crime has been committed.
Stopping a vehicle to investigate a possible DUI violation requires reasonable suspicion in the form of something to indicate the driver might have committed a crime. Reasonable suspicion is less than probable cause and could result from the officer observing a motorist doing any of the following:
- Failing to stay in lane
- Driving at speeds significantly below the speed limit
- Frequent or erratic braking
- Straddling the centerline
Reasonable suspicion authorizes an officer to stop the motorist to investigate.
Establishing probable cause for a DUI arrest
Once a motorist has been stopped, the officer will look for obvious signs of impairment to establish probable cause. These might include the officer observing the following characteristics or behaviors by the driver:
- An odor of alcohol coming from the vehicle or from the driver
- Glassy, bloodshot eyes
- Slurred speech
- Inability to concentrate and respond to question
The inability of a motorist to successfully complete field sobriety tests administered by the officer would add to the evidence of impairment and give police the probable cause required for an arrest.
A DUI defense lawyer can help
If you have been arrested and charged with DUI, let the criminal defense attorneys at Charles Law Offices in Allentown review your case to determine what defenses, including lack of probable cause might be available. Their aggressive, innovative defense strategies in DUI cases have achieved outstanding results.