Vehicle Code 40300.5 is an exception to the usual rule that an officer must personally witness a misdemeanor to make a warrantless arrest. It allows a warrantless DUI arrest in specific situations the officer did not see firsthand.
What it allows
Under 40300.5, an officer may arrest a person for DUI without a warrant when the person was involved in a traffic accident, was found in or near a vehicle obstructing a roadway, will not be apprehended unless arrested, may cause injury or damage to property unless arrested, or may destroy or conceal evidence unless arrested. The statute is most often used in collision cases where the officer arrives after the driving.
Why it is a point of challenge
Because the officer did not witness the driving, these cases often have gaps. The prosecution must still prove that you were the driver and that you were impaired while driving, not just afterward. The timeline between the driving and the testing, who was actually behind the wheel, and whether the statutory conditions for the warrantless arrest were met are all contestable. The rising blood alcohol defense is frequently relevant because of the delay.
Where to start
Accident-based DUI arrests under 40300.5 have real defenses built into their structure. Get a free written case analysis below or call me directly. See also DUI involving a collision and the no-driving defense.