Police evidence is usually the responsibility of the arresting police officer to obtain. It substantiates the enforcement action and is the basis on which the officer’s expert opinion is developed.

Below are brief descriptions of the 5 different categories of Police Evidence, each with a link to more extensive information designed to help anyone charged with a DUI/DWI/Drunk Driving to better understand the case being brought against him/her:

1. Driving Symptoms – This piece of police evidence is the first to attract an officer’s attention, unless an accident is involved. Many experienced prosecutors consider this to be the single most important piece of police evidence used to obtain a conviction.
2. Physical Symptoms – This piece of police evidence involves personal behavior and appearance. Symptoms of intoxication are extremely predicable, so much so, that many law enforcement agencies actually mass print them in extremely suggestive DUI/DWI reports for the arresting officer to fill out simply by checking off boxes.
3. Incriminating Statements – This piece of police evidence is often the most damaging in a drunk driving case because it comes from the defendant’s own mouth. NOTE: You are not required to answer any questions at any time.
4. Field Sobriety Tests (FSTs) – This piece of police evidence is usually administered at the scene of the arrest and involve three types of tests: performance, mental agility, or eye coordination. NOTE: These tests are not mandatory and that a suspect may refuse to take them with no legal consequences.
5. Chemical Evidence – This piece of police evidence involves either breath or blood tests. In 2000, urine tests were discontinued in California except when neither breath nor blood tests are available.