State v. Cowan - 260 Mont. 510, 861 P.2d 884 (1993)

Rule:

The existence of a mental disease or defect in a person does not necessarily preclude the person from acting purposely or knowingly.

Facts:

Defendant broke into a government-owned cabin and attacked the cabin's occupant when she returned, severely injuring her. Defendant was caught and charged with burglary and attempted deliberate homicide. Defendant suffered from paranoid schizophrenia, but was found competent to stand trial. The trial court convicted defendant in a bench trial and ordered him committed to the state department of institutions for placement in an appropriate facility. Defendant challenged the finding that he acted knowingly or purposely. Defendant contended that he did not have the requisite intent to commit the crimes due to his mental illness. 

Issue:

Did the defendant lack the requisite intent to commit the crimes due to his mental illness?

Answer:

No.

Conclusion:

The court affirmed the conviction because a trier of fact could have found that defendant possessed the required mental state to have committed the crimes. The presence of a mental illness did not necessarily preclude defendant from acting knowingly or purposely. Testimony from witnesses and experts indicated that defendant was coherent the day before the attack, that he mocked the occupant as she called for help, that he had a tendency to exaggerate his symptoms, and that he often lied to get out of trouble. The court also found that the homicide laws did not establish an unrebuttable presumption of criminal intent but merely established a permissive inference.