Can You Be Held Liable for a DUI When Unconscious?

by the Phoenix Arizona DUI attorneys at Ariano Reppucci

Most people probably think of a Driving Under the Influence (DUI) charge as relatively straightforward; you drink, drive your car after you drink, get pulled over because you may or may not be driving erratically, and take a field sobriety test. If you have a blood alcohol concentration (BAC) of over 0.08% after you were pulled over, you will be charged with a DUI.  However, there are a  variety of other issues involved, such as what substances can get you intoxicated (e.g. sedatives, stimulants, hallucinogens), what counts as a vehicle (e.g. tractors and motorcycles), and what counts as being in physical control of a vehicle (e.g. pulling over and waiting in the car while your key is in the ignition).

Can I be held liable for a DUI if I pulled over and passed out?

It depends on your circumstances and the state that you are arrested in. Generally, you should be conscious of your actions to be guilty of committing a crime. Unconsciousness is usually used as an affirmative defense to a DUI charge and is probably only available if you are involuntarily intoxicated.1

In Arizona it is uncertain as to whether you can use unconsciousness as an affirmative defense to a DUI case, although involuntary intoxication could be an option. If an officer has probable cause to determine that you are under the influence of alcohol or a controlled substance and you are unconscious, samples of your blood can be taken to determine whether or not you have such as substance in your body.2 This is the case because of Arizona’s implied consent laws. As soon as you obtain a driver’s license, you give your implied consent to these types of DUI tests (i.e. blood, urine, and breath) if the police officer has reason to believe you are intoxicated while in physical control of a vehicle.

Can unconsciousness be a defense?

Unconsciousness has been used as a defense in DUI cases in other states before. In one case, a driver who had taken a prescribed Ambien while at home claimed he was “sleep driving” and thus was unconscious when he was arrested.3 In the case, a doctor testified that sleep driving is a rare side effect of the drug that only happened in approximately 1,000 reported cases total.4 The California district court gave a jury instruction that said the defendant is not guilty of a DUI if he acted while legally unconscious.5 In California, unconsciousness not induced by voluntary intoxication is a complete defense to a criminal charge.6 The term “unconsciousness” in California means “where the subject phyiscally acts but is not, at the time, conscious of acting.”7 The California Court of Appeals found that the jury instruction on legal unconsciousness was flawed because it ignored expert testimony that a person can perform complex behaviors after ingesting Ambien and appear to be awake when he was not awake.8 Of course, a flaw in the jury instruction was not enough to save the defendant from a conviction, as it was a harmless error and this was not the defendant’s first DUI offense.9

Other states have heard cases where defendants who were charged with a DUI put forth the unconsciousness or sleep driving defense,10 but they often do not succeed if the defendant was in fact voluntarily intoxicated.11 While California and a variety of other states have had cases to flesh out whether or not unconscious driving can be a defense to drunk driving, Arizona has not had too much experience with the defense.

If you have been arrested under DUI statutes and you believe you have an involuntary intoxication defense, it is best to contact an Arizona DUI attorney. Your attorney will know which defenses you have according to your specific case.

[1] Gold & Witham, Defense of Unconsciousness in DUI Cases, (Sep. 12, 2013 3:45 PM),

2 Shawn Hamp, Arizona DUI Attorney Explains Implied Consent Statute,, (last visited Dec. 15, 2014).

3 People v. Mathson, 210 Cal. App. 4th 1297, 1301, 149 Cal. Rptr. 3d 167, 171 (2012).

4 Id. at 1304.

5 Id. at 1309-10.

6 Id. at 1312.

7 Id. at 1312.

8 Id. at 1317.

9 See generally, id.

10 Riley v. Com., 277 Va. 467, 470, 675 S.E.2d 168, 170 (2009).

11 Case v. Com., 63 Va. App. 14, 753 S.E.2d 860 (2014).