What Happens in a DUI Trial?
The first witness in most DUI cases is the arresting officer. Sitting there, listening to the direct testimony of the arresting officer in a drunk driving case is usually the most painful part of the trial, for defense attorney and client alike. The fact is that if the arresting officer doesn't have some damning stuff to say about the drunk driving arrest, the case should have gone away long before trial.
However, it is usually the cross-examination of that officer that becomes the bright spot of the case. The seasoned DUI defense lawyer will love cross-examination of the arresting officer as much or more than any other phase of the trial. Cross-examination has been described as the greatest legal engine towards the ascertainment of truth, and it is quite true in the DUI case.
Cross-examination in a DUI case, or any criminal defense case, for that matter, is not so much examination as it is the lawyer testifying. The most effective cross-examination occurs when a lawyer makes a short, declarative statement, and forces the witness to answer "yes." Each new "question" by the lawyer adds one new fact at a time, and the questioning proceeds to a logical goal, one goal at a time. When done in this fashion, cross-examination is one of the most satisfying and effective portions of the trial for the DUI defendant.
The second witness for the prosecution is typically a chemist from the crime lab. This person will give information regarding the breath or blood test, offer opinions regarding the field sobriety tests, and information about impairment from alcohol and how that impacts driving ability.
Just like cross-examination of the arresting officer, cross-examination of the prosecution's expert in a DUI case is incredibly satisfying, and can be extremely profitable for the DUI defense attorney and his client.
In order to prove the defendant's guilt, the prosecution usually focuses on four things: driving pattern, physical appearance, field sobriety test performance, and chemical test results. Cross-examination of the prosecution witnesses is designed to create reasonable doubt about how the defendant's performance in each of these areas is to be perceived, and to shift the focus from how the defendant did, to how well the tests were administered.