Q. 1. If a person is drunk or under the influence of drugs, is he guilty if he commits a crime? Or does the addiction reduce or annuls the guilt related to the sin. Some say, "If he was drunk, he could not have had the intent of committing the crime. So he is innocent."
A. 1. As indicated under "Sins: Mortal," three conditions must be met to commit a serious (mortal) sin. They are:
• It must be of a grave matter;
• It must be committed with full knowledge that it is a mortal sin;
• It must be committed with full consent. [Full consent means to do it "voluntarily."] (C.C.C. # 1857)
The question one must ask when determining if a person is guilty of his sin while under the influence of an addiction is, "What was the intent of the person prior to getting drunk or consuming drugs?"
Did the person plan on committing the serious crime? Was he aware that such an action was not only sinful in the eyes of God, but against the law of the land? In other words, did he know he was going to break the law? Did he proceed to commit the sin/crime voluntarily?
Some will say, "But he was drunk." Yes, he may have been drunk. But many addicts drink alcohol to gain the strength (to feel brave) to commit the crime and/or in the hope of being found not guilty of the crime if caught while under the influence of a substance.
Under the above mentioned circumstances, all three conditions are met and the person is guilty of his sin/crime. He had a free will and he chose to commit the crime while he was still able to reason and say "no, I will not do it."
While it cannot be denied that addiction lessens the freedom to choose, consequently reducing the guilt of the person, such can only be used if a person decided to commit the sin/crime while in an advance stage of addiction, as being "very drunk," not before consuming the alcohol.