The DUI checkpoint is one of the most reliable tools in the law enforcement toolkit for combating drunken driving. Checkpoints and traffic stops occur when the office has a reasonable belief that something illegal is taking place in the vehicle, i.e. drunken driving. The officer is permitted to question you and investigate to the extent that is necessary to test his reasonable suspicion but no further. This post will go over the limits to traffic stops and when you can challenge them.
There are two kinds of stops, traffic stops, and DUI checkpoints. At a checkpoint, the officer does not need reasonable suspicion to stop your car; he can do it simply because it is part of the checkpoint. Conversely, traffic stops require reasonable suspicion.
The reasonable suspicion must be supported by articulable facts. For example, if you were driving erratic, failed to signal, or drifted in and out of your lane. All of those incidents would suggest some form of impaired driving. Additionally, once the officer pulls you over and he notices bloodshot eyes, alcohol on your breath or any other factors, he can subject you to a field sobriety test.
But if the officer lacked reasonable suspicion, then the evidence that is gained from the stop was illegally obtained and may not be admitted as evidence.
If you were arrested under a traffic stop, then you may want to contact a defense attorney. As you can see, traffic stops are highly regulated events. The police officer must comply with every requirement, or any evidence that is gleaned from the stop is thrown out of court. A defense attorney can go over the details of your traffic stop and the steps you may need to take to prove your innocence.