A DUI / DWI attorney preparing to defend a client’s drunk driving case typically will prepare pretrial motions in an effort to improve the client’s prospects in court. A motion is a formal legal document asking the court to take a particular action. One of the most common motions introduced in a drinking and driving case is a motion to suppress evidence also called a motion in limine.
In a drunk driving case, a suppression motion generally will question whether the arresting officer had probable cause to make a traffic stop or an arrest, the results of the chemical tests administered to determine blood alcohol content (BAC), or both.
A motion to suppress based on whether or not the officer had probable cause to make a traffic stop likely will center around whether or not the officer had a reasonable belief that a crime was being committed. If the motion is successful, statements or testimony obtained as the result of an unlawful detention, arrest, or search are subject to suppression.
Probable cause for a traffic stop can be established by any California Vehicle Code violation; however, the violation must occur in the officer’s presence. It is unlawful for police to stop a car in order to determine whether the driver can produce a valid license and registration. It is also unlawful to stop a vehicle in the anticipation of discovering a vehicle code violation or other contraband, such as drugs, when no actual probable cause has presented itself to the officer before the stop.
Some drunk driving arrests stem from anonymous tips made by third parties. In the case of anonymous tips, police may only make an arrest for Driving Under the Influence if an officer witnesses behavior that provides a reasonable suspicion that the driver is intoxicated. If the arrest was based solely on the third-party tip, the arrest is unlawful, and any evidence gathered must be suppressed.
A motion to suppress the results of a chemical test generally focuses on whether the test was properly conducted. If any of the strict guidelines governing the administration of chemical tests were not followed, the evidence likely will be suppressed. If this occurs, evidence gained as a result of the test also would be suppressed, such as observations of signs and symptoms of intoxication. A motion to suppress can be brought on several different grounds and in several different situations.
Evidence that prosecutors seek to present in DUI / DWI cases isn’t automatically admissible – it must meet strict legal requirements to be used at trial. A lawyer who specializes in defending drunk driving cases can challenge evidence that may be inadmissible, and vastly improve a driver’s prospects at trial.