Amnesia: A Defense to Criminal Charges?

To be responsible for most crimes, defendants must act knowingly or recklessly. This mental state requirement acts to distinguish those who might accidentally do something (such as tripping and pushing someone down while falling) versus those who intentionally do something (such as angrily shoving someone and injuring them). The intentional act makes the person morally blameworthy and responsible for committing a crime.

So what happens if the defendant doesn't remember what happened? Is amnesia a valid defense to a criminal act? For the most part, no. But memory loss might influence a criminal proceeding in other ways.

What Is Crime-Related Amnesia?

Amnesia refers to the partial or total inability to recall past memories or to store new memories. There are numerous causes of amnesia from physical injuries and strokes to old age and neurological diseases.

Types of Crime-Related Amnesia

Claims of crime-related amnesia typically fall under one of three categories: dissociative, neurological defect, and malingering.

A person might claim dissociative amnesia if they fail to remember an event due to extreme emotional stress or trauma (more common with violent crime). Amnesia caused by a neurological defect isn't necessarily related to the criminal event. It could be associated with traumatic brain injury, psychosis, or organic disease. This type of amnesia can also occur with drug or alcohol use, but voluntary intoxication doesn't typically excuse a person from committing a crime. Lastly, malingering amnesia refers to feigned memory loss, which undermines the legitimacy of amnesia defenses in general.

Amnesia and Legal Implications

In the criminal context, amnesia may be relevant to an offender's mental state when committing a crime (criminal responsibility), standing trial (competency), or determining the penalty (mitigating factor). But courts do not recognize amnesia as its own defense.

Amnesia and Criminal Responsibility

For most crimes, the law requires a prosecutor to prove a particular mental state of the defendant at the time of committing the crime. A person's memory, though, isn't the same as the mental state required to commit a crime. The inability to remember committing a crime doesn't necessarily mean the defendant didn't intend to and actually commit it.

If, however, a defendant can show the amnesia interfered with the ability to form intent to commit a crime when the crime was committed, it could create conditions for an insanity defense (albeit rarely successful).

Example: Amnesia caused by chronic alcoholism wasn't a defense to forgery. Even though the defendant couldn't recall his actions at the time he forged the signature on the check, his memory loss didn't affect his intent to commit the fraudulent act. (People v. Hibbler, 274 N.E.2d 101 (Ill. 1971).)

Example: The court upheld the defendant's homicide conviction because his failure to remember the shooting wasn't proof of his mental condition at the time of the act. His memory loss wasn't evidence that he didn't know right from wrong when the crime occurred. (Lester v. State, 370 S.W.2d 405 (Tenn. 1963).)

Amnesia and Competency to Stand Trial

A judge can consider amnesia when determining whether someone is competent to stand trial. When considering whether amnesia compromises one's ability to stand trial, courts look at factors like the following:

• whether the defendant is able to discuss the defense of the case
• whether the amnesia is temporary or permanent
• whether the crime can be reconstructed without the defendant's testimony
• whether the government's files can help in preparing the case, and
• the strength of the government's case.

In some cases, temporary amnesia could justify a delay in the trial to regain competency. But, generally speaking, judges don't grant such delays lightly.

Example: The defendant received a fair trial despite his claim of incompetency due to his inability to recall the events of the crime. There was no indication that he didn't understand the charges, that he wasn't able to understand the events on the day of the crime, or that he couldn't assist his attorney in defending against the charges. (Morris v. State, 214 S.W.3d 159 (Tex. App. 2007).)

Example: Amnesia does not automatically make a defendant incompetent to stand trial. It must be an extraordinary situation that comprises a defendant's ability to think rationally at the time of trial. Several courts have found amnesia more akin to missing evidence and lack of recollection or blackouts suffered by many defendants due to the passage of time, intoxication, or stress during the event. (Gonzales v. State, 313 S.W.3d 840 (Tex. App. 2010); State v Willard, 234 S.E.2d 587 (N.C. 1977).)

Amnesia and Sentencing

While a claim of amnesia is rarely determinative of guilt or innocence, the judge or jury can consider it when deciding the penalty for the crime.

Example: Amnesia occurring after the crime wasn't admissible to prove the defendant's motives or conduct at the time of the murder. But if the judge or jury believed the defendant actually suffered from it, amnesia could be considered in determining the penalty. (Commonwealth ex. rel. Cummins v. Price, 218 A.2d 758 (Pa. 1966).)

Example: The Delaware Supreme Court upheld jury instructions that allowed the jury to consider the defendant's amnesia only for sentencing purposes but not to resolve matters of guilt. If the jury believed the defendant suffered from amnesia, it could choose to recommend mercy in light of the death penalty. (Parson v. State, 275 A.2d 777 (Del. 1971).)

Getting Legal Help

If you face criminal charges, talk to a criminal defense attorney. A lawyer can help evaluate your case and any possible defenses.