The most important step is to review the DMV 367 Form. This is the form the officer filled out after the arrest. Looking for missed signatures, dates, times etc. are very important to winning the DMV hearing. Most important is the Chemical Test Result box (if a chemical test was conducted). The box must contain a signature and date of the officer that administered the test. Also, page two of the DS 367 must contain the officer's statement or the reason the subject was stopped. There must be a lawful reason for the stop or the stop is deemed unlawful and the hearing is won.
Review the DUI Investigation Report & Test Results
The officer will also include the DUI Investigation Report in the evidence submitted to the DMV. It is important to review these forms to see if they comport with the DMV forms. Be sure to cross reference dates and times and the reason for the contact or stop. When reviewing the test results of a breath test, make sure the machine accurately stated the results. Often times, a subpoena supplied by the DMV can be issued to the police department where the machine is located to get maintenance and calibration records to see if the machine was in proper working condition. If the machine was not working properly, a Forensic Toxicologist can testify at the DMV hearing. These are just a few potential defenses.