A police officer only needs suspicion of criminal activity to justify a traffic stop. This standard is less than probable cause and an observation of an actual traffic violation is not necessary. If you were swerving in the lanes, an officer may be able to justify the stop. It all depends on the circumstances of each case. If the stop was illegal, the evidence obtained as a result of the stop can not be used against you.
You should have your case reviewed by an experienced Minnesota DWI lawyer to find the loopholes. Contact Robert J. Shane at (612) 339-1024 or visit his website at www.criminallawyerminnesota.com.