Drunk driving or driving under the influence of alcohol or drugs (DUI) is a strict liability offense in most US states. This means that the prosecution does not have to prove that the driver intended to drive while intoxicated; it is based on the doctrine of foreseeable results.
But there are instances where the defendant had no intention of getting intoxicated. One scenario is when a prescribed medication induced intoxication and the side effect is not included in the list of contraindications in the medication’s instructions. Another is the ingestion of an intoxicating substance was unknowingly ingested, such as at a high school party where the punch was spiked with alcohol as a prank, and the defendant did not know. Still another is when space cakes or hash brownies are served at a party, and the defendant ate them without knowing they contained marijuana. This could also be classified as a mistake of fact, an element of the involuntary intoxication plea.
Some jurisdictions such as California expressly states that an individual who can prove involuntary intoxication cannot be convicted of a crime because they committed the offense without being conscious of it and could not have foreseen the consequences. The sting in that needle is in proving the element of free will, which is the burden of the defense.
For the defense to work, it also has to be shown that the defendant in no way intended to get intoxicated. For example, if the defendant went to a party and drank a cocktail that was more potent than anticipated, the resulting intoxication cannot be said to be involuntary as the defendant did willingly ingest alcohol. Taking medication that was clearly marked as contraindicated when driving is also not compatible with involuntary intoxication.
There are many elements that would need to come together for a successful involuntary intoxication defense, and not all jurisdictions accept it as a viable defense. It is up to the criminal defense lawyer to make the call.