The sudden siren and flashing blue and red lights of a police vehicle behind you. If you have been arrested on suspicion of DUI in Pennsylvania, you know the sickening feeling you get when an officer pulls you over. In the moment, you were probably too startled and nervous to wonder if the officer practiced proper procedure by pulling you over. But whether or not the police violated your rights during your traffic stop could make the difference between a conviction and a dismissal of the charges against you.
When is a DUI traffic stop illegal?
The law states that police officers and state troopers cannot pull over vehicles at random. They must have a reasonable, articulable suspicion that the driver is committing or has committed a crime. This is known as probable cause. Most of the time, this means the officer must be able to say they observed a driver drifting out of their lane, making sudden starts or stops, or otherwise displaying signs of intoxication.
If the evidence suggests that the arresting officer lacked probable cause to pull you over, they may have violated your rights and any DUI charges you face could get dismissed.
Searches and seizures
The focus of most traffic stops based on suspected drinking and driving is the officer’s attempt to conduct a search and seizure. In fact, pulling you over is a type of “seizure” of yourself and your vehicle, since you are not free to leave the scene unless the officer permits you.
While the Fourth Amendment to the Constitution prohibits searches and seizures without first getting a search warrant, there are several exceptions. One exception is when you are pulled over due to probable cause of DUI. In that case, the officer has the right to search your body (in this case, your breath) without a warrant. But again, if the officer lacked probable cause to pull you over in the first place, any evidence gathered against you during the traffic stop can be thrown out of court as illegally obtained evidence.
It is usually impossible to challenge the validity of a police stop while it is happening. Such challenges happen in court later.