Intoxication due to a defendant’s voluntary consumption of drugs or alcohol isn’t usually a defense to criminal charges—but if the intoxication was involuntary, it may be a defense on the basis that the defendant did not understand what he was doing or that what he was doing was wrong. And some states allow a defendant to assert a defense that his voluntary intoxication prevented him from forming the specific intent to commit the crime (attempted murder, for example). But this is a question of fact that the jury will usually determine.

The availability and definition of any defense to criminal charges based on the defendant’s voluntary or involuntary intoxication is usually located in a state’s statutes—often in the penal or criminal code.

In Colorado, voluntary intoxication is generally not a defense to criminal charges. However, under Colorado law, there is an exception where voluntary intoxication can be considered when it negates the specific intent required for certain crimes. This means that if a defendant was so intoxicated that they could not form the specific intent necessary to commit a crime like attempted murder, they may use this as a defense. On the other hand, involuntary intoxication can be a defense if it can be shown that the defendant was unable to understand the nature of their actions or that their actions were wrong due to the intoxication. The nuances of these defenses and their applicability are typically determined by the jury and are based on the specific facts of the case. These defenses are codified in Colorado's statutes, which can be found in the state's penal or criminal code.