Based on the Fourth and Fourteenth Amendments to the United States Constitution, the police must have an adequate reason before they stop your vehicle.
All states, other than California, have state constitutional protections that offer equal or better protections to those found in the federal constitution. California lacks such protections due to the voters being hoodwinked into voting to give up any state constitutional protections that offer greater protection of their liberties than the rights that exist under the United States Constitution.
Once stopped by the police, any indication of possible impairment from alcohol or drugs will lead to a DUI-DWI investigation. A very minor tag irregularity or vehicle equipment problem will authorize an officer to pull the car over, even if the officer’s real purpose is to look for other possible criminal activity.
If the “reason” for the stop is not proper (i.e., not legally sufficient), then from the start of your detention, all further evidence gathered by the police is not admissible in court and all alcohol or drug related charges arising from this incident can be dismissed if a proper motion is filed by your criminal law specialist.
Once a motion is filed [typically a “motion to suppress” or a “motion in limine” (a motion to limit the use of evidence)] the trial judge will be asked to review the legitimacy of the traffic stop. This chapter discusses some of the most common legal challenges your attorney might raise on your behalf at a pre-trial motion hearing. Your chances of success will often be based on all of the details you provide during your interview process when you tell your attorney your version of what happened at the time of your arrest.
In addition to your account of the incident details, the officer’s video or audio tape (if any), police report, traffic citations, other documents of your arrest, detention, vehicle towing and bonding out of jail will be of great value to your attorney. If you took any DUI breath test, the printed evidential cards showing these results will also be important.