Police officers must make a finding of probable cause to stop the driver of a motor vehicle in a DUI case. If the officers lacked sufficient cause, any evidence obtained as a result of the stop, which would likely include all evidence except observations of driving, must be suppressed by the Court. Any request for suppression must be made within 28 days of entering a plea of not guilty. If probable cause for the stop existed, the prosecution still must justify the investigatory detention. Again, if there are insufficient facts to warrant detaining the driver beyond a temporary stop, then it may be possible to suppress the evidence. If successful, this will suppress all evidence but observations and statements made during the brief stop. Finally, if there existed probable cause to detain the individual for a field investigation, the officers still must show evidence of intoxication to warrant an arrest. The prosecution’s failure to meet these standards of probable cause may result in a judge suppressing all evidence obtained after the driver establishes a failure to find probable cause. Please consult an Idaho DUI attorney because there are also numerous Idaho and federal cases that interpret “probable cause”.