An Invalid Stop A police officer must have 'reasonable suspicion' to stop a vehicle. In other words, an investigating officer must have a clear and specific reason for making a traffic stop in the first place. This is referred to as reasonable suspicion. Some vague notion of suspicion is not enough. Traffic stops for actions that do not amount to a specific traffic violation can be challenged as not reasonable. If your challenge is successful, all evidence obtained after the stop is suppressed, that is, thrown out of court. Errors in handling Roadside Sobriety Tests An officer can stop you with only reasonable suspicion, but in order to make an arrest he or she must have something more called, probable cause. The standard way to establish probable cause is thru roadside sobriety tests. If an officer performs the tests improperly that can lead to the suppression of evidence or even dismissal of the case. At a minimum, it calls the officers opinion and competence into question, which just might be enough to cause reasonable doubt and win the case. Errors and Inconsistency in Reporting Once you have read a few DUI police reports, you begin to realize that officers say the same things over and over again. For example, 99 out of 100 DUI reports will say, "As I approached the vehicle I smelled the odor of an unknown intoxicating beverage. The suspects eyes were bloodshot and watery and his speech was slurred." What officers obviously do is use a prior report as a template or cut and paste from another report. This sometimes gets them in trouble if they don't adequately proofread the report. If, for example, the officer refers to a male defendant as she in several places, it is fairly obvious that he is copying facts. Even if the mistake seems unimportant it calls into question the entire report. What other 'facts" did he copy and paste? Additionally, if the times don't match up to say a 911 call, this can call into question the officers ability to fairly and accurately write a report. A good attorney will know every word of the police report and point out and testimony that is inconsistent or contradictory. Failure to Take a Timely Blood or Breath Test It is well known that a persons blood alcohol content (BAC) can continue to rise long after the person has stopped drinking. Very frequently a person might be diving legally, and only later does their blood alcohol level rise above the .08 limit. In Nevada a test is presumed inaccurate if it is taken more than two hours after the person was driving. But how else might we show that the BAC has been rising and create some reasonable doubt of guilt? Sometimes, an officer with give a preliminary roadside breath test. If that test is substantially lower than the official test that demonstrates a rising BAC. If the suspect performed some roadside sobriety tests fairly well, that can indicate that blood alcohol levels were on the rise. Additionally, if the official blood or breath test is borderline it can call into doubt if the blood alcohol level was on the way up or on the way down. Remember, it's the State's duty to show guilt beyond a reasonable doubt, not the defendants duty to prove he or she is innocent. Officer Mistakes in their Testimony Very often there is a video of the stop, tests, and arrest. If the officer on the stand makes mistakes in recalling the times, and events that took place, that can call into question his entire testimony. A good attorney tests the officer's recollection and will trap the officer if he is not testifying accurately or honestly. Again, an accused does not have to prove innocence, they must merely show reasonable doubt as to the facts of the case. That's a fairly high standard, but it is the cornerstone of our entire justice system. Each of us are innocent until proven guilty. Bonus Mistake #6, Disrespect There are a lot of good and honest police officers out there. However, too many officers view the entire criminal justice system as some kind of game. They resent a citizens exercise of constitutional rights at the expense of their investigation. They laugh, or are disrespectful to the suspects, the witnesses, and attorneys, and sometimes even the judge or jury. This kind of disrespect has no place in our justice system. If an officer treats a suspect poorly, it calls into question his fairness and professionalism.