Understanding Volitional Movement in California DUI Cases
California Vehicle Code section 23152 requires proof of volitional movement of a vehicle to establish a DUI offense. To satisfy this element, the prosecution must show that the defendant intentionally moved the vehicle; however, the quantum of movement required is minimal.
We have cases that have been one at DMV Hearings because the person was outside of their car when arrested and there was no showing of what his/her blood alcohol level was at the time the person was in the car. The person has to be "drunk" at the same time the car was moved. The other issue is the "how much does it have to move"? That law is bad for the defendant.
Minimal Movement Suffices
In Mercer v. Dept. of Motor Vehicles (1991), the California Supreme Court confirmed that volitional movement is necessary to prove “driving,” while clarifying that the movement need not be extensive. The Court explained that even slight, intentional movement satisfies the statutory requirement. Padilla v. Meese (1986) is in accord, holding that minimal, intentional movement is adequate to establish the act of driving. Similarly, Henslee v. Dept. of Motor Vehicles (1985) reiterated that slight movement may establish the element of driving for DUI purposes.
The holding in Mercer v. Department of Motor Vehicles (1991) 53 Cal.3d 753, was that an officer must observe some volitional movement of a vehicle. A person who is merely "in actual physical control" of a parked vehicle while intoxicated is not "driving. This supports the I fell asleep in my car defense, I got kicked out of my house by my spouse defense and other similar explanations as to why someone was in the car drunk but did not drive. However beware of Tesla's and other cars that record your movement. With a warrant police can get that data and may be able to prove volitional movement of the car (if they can prove that the car moved and ALSO that you were the driver).
On a strange note - what if you are drunk and you use the command on your Tesla app that parks your car in your garage. Is that "driving"?
Circumstantial Evidence of Driving
Our clients will sometimes say "No one saw me drive". That is a defense except when it is not.
Driving may be proven through circumstantial evidence. Mercer recognized that direct observation is not required and that a factfinder may infer driving from surrounding facts. For example, in People v. Wilson (1985), the court found sufficient evidence of driving where officers discovered a vehicle parked on a freeway, far from an on-ramp, with the defendant in the driver’s seat and the engine running. Those circumstances supported a reasonable inference that the defendant had volitionally driven the vehicle to that location.
Jury Guidance: CALCRIM No. 2241
CALCRIM No. 2241 provides jurors guidance on the meaning of “driver” and “driving” in DUI cases, instructing that the element may be established by circumstantial evidence and that slight, intentional movement is sufficient. Jurors are directed to evaluate all the evidence—direct and indirect—bearing on whether the defendant moved the vehicle volitionally.
Practical Implications
These principles shape both prosecution and defense strategies. Prosecutors may rely on circumstantial facts—vehicle location, engine status, driver position, and other indicia—to prove volitional movement even absent eyewitness testimony of driving. Defense counsel can challenge whether the evidence reasonably supports an inference of intentional movement, emphasizing gaps such as alternative drivers, vehicle towing or rolling, or non-volitional movement. This framework maintains the statutory standard while safeguarding the accused’s rights by requiring proof of intentional movement.
The Best DUI Defense
The best DUI defense comes from experienced criminal defense lawyers. When dealing with priors your lawyer needs to aggressively review and challenge prior convictions and map a strategy for your defense. The Law Office of Daniel Horowitz is expert in DUI and criminal defense. To schedule in an initial consultation, call the office at (925) 283-1863. We have only live people on site answering our calls - no AI, no offshore message takers - Real People who know your case.
