Supreme Judicial Court (August 23, 2010)

The defendant was charged with the murder of an acquaintance. During her trial, her defense was that she was not criminally responsible for her actions because of a head injury she received at a young age, several psychiatric hospitalizations, a brain tumor, and substance abuse. The defendant was convicted of first degree murder. She appealed, claiming that the judge's instruction to the jury did not make clear that a voluntary consumption of alcohol which activates or intensifies a preexisting mental illness and causes the defendant to lose the substantial capacity to appreciate the wrongfulness of his conduct or the substantial capacity to conform his conduct to the requirements of the law, may be the basis for a finding of not guilty by reason of lack of criminal responsibility.

The instruction given by the judge at trial was based on court decisions concerning the combination of mental disease and the voluntary consumption of drugs or alcohol. However, the SJC found that when applied to the facts of this case, the jury instruction "did not properly instruct the jury," and the defendant's conviction was overturned. "Where only the model instruction was given, the jury could have believed that, even where a defendant lacked the substantial capacity to conform her conduct to the law as a result of her mental disease or defect, that defense would be defeated by the voluntary consumption of any alcohol that exacerbated her condition."

The Court went on to write a jury instruction that may be used in homicide cases where there is evidence that a defendant had a mental disease or
defect and consumed drugs or alcohol:

" A defendant's lack of criminal responsibility cannot be solely the product of intoxication caused by her voluntary consumption of alcohol or another drug. [Commonwealth v. Sheehan, 376 Mass. 765, 770 (1978).]

"However, a defendant is not criminally responsible if you have a reasonable doubt as to whether, when the crime was committed, the defendant had a latent mental disease or defect that became activated by the voluntary consumption of drugs or alcohol, or an active mental disease or defect that became intensified by the voluntary consumption of drugs or alcohol, which activated or intensified mental disease or defect then caused her to lose the substantial capacity to appreciate the wrongfulness of her conduct or the substantial capacity to conform her conduct to the requirements of the law. If you have a reasonable doubt as to whether the defendant was criminally responsible, you shall find the defendant not guilty by reason of lack of criminal responsibility.[ [FN9]] [Commonwealth v. Herd, 413 Mass. 834, 841 (1992). Commonwealth v. McGrath, 358 Mass. 314 (1970).]

"Where a defendant has an active mental disease or defect that caused her to lose the substantial capacity to appreciate the wrongfulness of her conduct or the substantial capacity to conform her conduct to the requirements of the law, the defendant's consumption of alcohol or another drug cannot preclude the defense of lack of criminal responsibility."