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 Tennessee, as in many states, voluntary intoxication is generally not a defense to criminal charges. Tennessee law holds that voluntary intoxication is not an excuse for criminal conduct and cannot be used as a defense to negate the required mental state of a crime. However, involuntary intoxication can be a defense if it can be shown that the defendant was incapable of forming the requisite intent to commit the crime due to the intoxication being involuntary. This might occur if the defendant was drugged without their knowledge or consent. The distinction between voluntary and involuntary intoxication is significant, and the burden of proof lies with the defense to establish the involuntary nature of the intoxication. Whether intoxication was voluntary or involuntary, and whether it prevented the defendant from forming the specific intent required for a particular crime, are questions of fact typically left to the jury to determine. The relevant statutes and case law in Tennessee would provide the specific legal framework for these defenses.