Police are uniformly trained to detect impaired drugged / drunk driving through the National Highway Traffic Safety Administration. In that capacity, they are trained to look for 24 cues that a driver may exhibit to form a basis for what is lawfully needed to stop you. A police officer always needs "probable cause" to stop you to investigate whether you might be involved in a criminal matter. Generally, probable cause means a reasonable articulable suspicion by the police that you are, have, or are about to commit a crime. Without probable cause the police are precluded from pulling you over while traveling in your car or truck. As such, probable cause, or lack thereof, is one the very first things analyzed by your criminal defense attorney when dealing with a criminal allegation against there client resulting from an automobile stop and search - including DUI's and unlawful possession.
But what if the only reaason you were pulled over was becuase someone you may not even know called the police or 911 and said you were involved with breaking the law? Can the police pull you over just on an anonymous tip?
The answer is maybe but not always. This will depend on the totality of the circumstances surrounding the information provided to the police, which must be of sufficient quantity and quality to enable the police officer to have reasonable suspicion. These circumstances include whether the caller was anonymous and did not supply their identity and the quality and detail of the information provided by the caller - whether they were anonymous or actually provided their name.
The United States Supreme Court held in Navarette v. California, 572 U.S. 393 (2014) that police can stop someone if the information obtained from an anonymous informant provides enough detail to create reasonable suspicion of a crime. This ruling, although very controversial, has been observed by the West Virginia Supreme Court as well in State v. Stuart, 192 W.Va. 428, 452 S.E.2d 886 (1994); State v. Ciccone, No. 13-0821 (June 5, 2014). In West Virignia "A police officer may rely upon an anonymous call if subsequent police work or other facts support its reliability and thereby, it is sufficiently corroborated to justify the investigatory stop under the reasonble suspicion standard."
As you can imagine, there exists a very broad and grey area where your attorney must work in order to preserve your constitional right to be free from unlawful automobile stops and searches when you have been pulled over becuase of an anonymous tip. If your attorney is successful in demonstrating that the information provided to the police was insufficient as a matter of law, this can mean that all evidence observed by the investigating officer (i.e. your alleged exhibted impairment) and the items of alleged contraband retrieved from your auto will be suppressed and will be unable to be admitted into evidence at the trial against you.
Probable cause is one of the very first issues your attorney will assess in any criminal allegation that comes from being pulled over in a motor vehicle. Many times it is the difference between a winning and losing trial strategy.