Any time a police officer pulls someone over; they must have some legal basis for the stop. In order for such a legal basis to exist, the officer must have been able to see the driver doing something that violated one or more laws. The requirement that there be a legal basis for every vehicle stop is called probable cause. Any arrest that arises from a vehicle stop that was conducted without probable cause is invalid. Because a lack of probable cause invalidates an arrest, lack of probable cause is an important defense against DUI charges.
A police officer cannot simply say that they had probable cause to stop your vehicle. They must be able to describe the conduct that they observed that was a violation of the law. For example, if you failed to stop at a stop sign and the officer observed you as you went through the intersection without stopping, they would say that they had probable cause to stop your vehicle because it failed to stop at a stop sign. Some of the reasons that officers try to provide as evidence of probable cause are not observable violations of the law. For example, no driver remains exactly in the center of their lane all of the time. If an officer claims that they had probable cause to stop your vehicle because your vehicle was weaving within your lane, that may not be enough to support a finding that there was probable cause to stop you. If, on the other hand, an experienced law enforcement officer sees a driver weaving in a dramatic fashion for a substantial distance, that observation would likely support a finding that there was in fact probable cause for the stop.
In addition to having probable cause to make the stop, a law enforcement officer must also have probable cause to make an arrest. When you are stopped and the officer comes to your window and checks your license and registration, they also observe you for signs of intoxication. In order to arrest you, they must see something that would cause a reasonable officer to believe that you were driving while under the influence of alcohol. If the officer could not have observed anything that would have given them probable cause to arrest you, you may be able to have evidence like blood or breath tests that were obtained after the arrest excluded from evidence. This is called suppression, and it is a very effective way to defend against DUI charges.
If there is a possibility that the police officer who arrested you did not have probable cause for the vehicle stop, the arrest, or both, it is possible that the lack of probable cause could be the basis for a successful defense against your DUI charges. A Kansas DUI Defense Attorney can help you to reduce your chances of being convicted of driving under the influence of alcohol. To learn more about probable cause and other defenses against Kansas DUI charges, please call (316) 264-1548.