One of the primary issues that comes up in Defending against DUI charges and cases is assessing whether or not the police had probable cause to stop a vehicle to begin with. Under Pennsylvania DUI law, a criminal defendant may only be convicted of the crime of DUI if the police possessed probable cause to stop the defendant while he was driving his car. Defending Dui Cases In order for the police to perform a traffic stop, they must possess probable cause that the defendant was committing a criminal or vehicle code violation. In a DUI case, the Judge will dismiss the DUI charges if the government cannot prove that the officer possessed probable cause that the defendant was committing a traffic violation when he stopped the vehicle and discovered that the driver was driving under the influence.

So let’s look at some examples of when the police may and may not stop your vehicle. May the police stop a vehicle because a Defendant was told to stop sounding his horn and to remove his vehicle from the intersection and did not? In such a case a Defendant would be charged with a violation under 75 Pa.C.S. § 3351(a) for an alleged improper stop of his vehicle upon the roadway. This law states that a person may stop his car in a roadway “when it is practicable to stop, park or stand the vehicle off the roadway.” DUI closed roadway This provision does not apply to disabled vehicles. In one DUI case, the Pennsylvania Superior Court determined that the officer had probable cause to stop the defendant for a violation of § 3351(a) when his truck was stopped motionless “in the middle of the flow of traffic.” In that case, defendant’s actions caused a backup of “three to four cars” as defendant sat in the intersection “through at least two cycles of the traffic light turning green. Accordingly, a vehicle may be stopped if the defendant impeded the flow of traffic or sat in the intersection unnecessarily.

In another case a higher court found that probable cause was determined to be lacking when erratic driving is “momentary and minor.” In that case, appellant drove over the right berm line of the road two times, each in response to another car coming towards appellant in the opposite lane of travel. Appellant was observed for just two blocks, so the conduct took place over a short period of time. Accordingly, the momentary and minor exception may apply if Defendant’s conduct, while technically illegal, is reasonable, momentary, and minor given the totality of the circumstances.