One of the most commonly used challenges to a DUI Checkpoint and/or Roadblock is to demonstrate a lack of uniformity in the operation of the checkpoint.
Regarding the issue concerning the required limits on the discretion of field officers, the California Supreme Court in Ingersoll v. Palmer, noted the following:
A related concern is that motorist should not be subject to the unbridled discretion of the officer in the field as to who is to be stopped. Instead, a neutral formula such as every driver or every third, fifth or tenth driver, should be employed. To permit an officer to determine to stop any particular driver or car when there is no legitimate basis for the determination would be to sanction the kind of unconstrained and standardless discretion which the United State Supreme Court sought to circumcise in its decision in Prouse, [citations omitted]. In all the checkpoint programs at issue here, neutral mathematical selection criteria were used.
Id., at 1342 (emphasis added)
Post checkpoint records, available through discovery, will demonstrate the pattern of detentions. Every car or every third car is neutral. A change in patterns to adjust for traffic flow is also neutral so long as there is a formula for the change. What is prohibited is an unjustified deviation from the pattern which negates the neutral mathematical formula. If the pattern suddenly changes randomly, an inference of non-neutrality arises making the checkpoint potentially unconstitutional.
To learn more about DUI Checkpoints and/or Roadblocks, read these other posts:
DUI Checkpoints (Part I) - The Evolution of DUI Checkpoints & Roadblocks
DUI Checkpoints (Part II) - The Neutral Mathematical Formula Requirement
DUI Checkpoints (Part III) - The Time and Duration Requirements
DUI Checkpoints (Part IV) - The Advanced Publicity Requirement
DUI Checkpoints (Part V) - Detentions for Avoiding a DUI Checkpoint
If you were arrested at a DUI Checkpoint, contact Peter F. Iocona, Attorney at Law and one of the experienced Orange County DUI Lawyers from The SoCal Law Network today for a free DUI Consultation and Case Evaluation.