Police are required to follow specific rules and protocols when investigating a suspected DUI driver and making a subsequent arrest. However, if any part of this procedure was not obeyed by law enforcement, the arrest may be considered invalid and any evidence collected can be thrown out in court. In some cases, such evidence that is dismissed at trial is so important that the prosecutor doesn't have a case without it, which can result in dismissal of the entire case.
The following are the most common mistakes made by police during a DUI investigation:
- Insufficient traffic stop – In order for the police to pull a suspect over, they need to have “reasonable suspicion” for doing so. In most cases, this means evidence of a traffic violation, such as driving over the speed limit, changing lanes without signaling or driving with a busted taillight. If law enforcement doesn't have reasonable suspicion, the evidence obtained at the scene is considered invalid.
- No probable cause – Police need to have probable cause prior to making an arrest. This means that law enforcement needs to find certain facts that would lead a reasonable officer to think that the suspect is intoxicated. Without such facts, the police cannot make a proper arrest.
- Failure to properly administer field sobriety tests (FSTs) – These tests are used to determine whether a suspect is intoxicated prior to arrest. However, FSTs must be administered according to the NHTSA guidelines. Failure to properly administer these test means the FST evidence is inadmissible in court.
- Failure to properly administer chemical tests – After a DUI arrest, the suspect will be asked to take a breath, blood or urine test. Police are properly and certified to administer the chemical test. If an officer fails to properly calibrate the device prior to testing or fails to follow the proper protocol, then the test results are considered invalid.
If you have been arrested for DUI in California, it is important to hire an experienced criminal defense lawyer to fight for your freedom. An attorney can evaluate your case, determine if potential mistakes were made by police during the investigation, and build a strong defense strategy to either get your entire case dismissed or your charges reduced.