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 Massachusetts, voluntary intoxication is generally not a defense to criminal charges. However, there are exceptions where voluntary intoxication may be considered by the court, particularly in cases where specific intent is an element of the crime. For example, if a defendant is charged with a crime that requires the prosecution to prove intent beyond a reasonable doubt, evidence of the defendant's intoxication may be relevant to whether they were capable of forming that intent. Involuntary intoxication, on the other hand, can be a defense if the defendant can show that they were intoxicated without their knowledge or against their will, and as a result, they were unable to understand the nature or wrongfulness of their actions. The specifics of how intoxication affects criminal liability can be found in the Massachusetts General Laws, particularly within the penal or criminal code sections that deal with defenses to criminal charges. It is important to note that the applicability of these defenses is often a question of fact for the jury to determine based on the evidence presented at trial.