Chapter 5

• Jurisdiction: United States

Chapter 5 Mental Defense

Insanity

On August 6, 1973, Simon L. Dearbone, age twenty-eight, was released from the Veteran's Hospital at American Lake in Tacoma, Washington, where he was being treated for mental illness. Five days later Dearbone threatened his cousin Matthew Jones, age forty-five, with a butcher knife and then beat him to death with a rock.

Dearbone left Jones's body in an eighteen-foot-deep sewer line excavation in Pine Lake Highlands north of Issaquah, Washington. Dearbone's reason for killing Jones was that Jones had hit Dearbone's thirteen-year-old girlfriend with a wine bottle in February. This is the summary of what I told the jury of ten women and two men, with two men as alternates, in my opening statement on December 5, 1973.

The defense in the case was insanity. The state of Washington adheres to the M'Naghten Rule that was enacted by the English House of Lords in the mid-nineteenth century. The right-from-wrong M'Naghten Rule was phrased this way:

Every man is presumed to be sane, and ... that to establish a defense on the ground of insanity, it must be clearly proved that, at the time of the committing of the act, the party accused was laboring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing; or, if he did know it, that he did not know he was doing what was wrong.

The M'Naghten Rule is codified in Washington statute RCW 9A.12.010 as follows:

To establish the defense of insanity, it must be shown that:

1. At the time of the commission of the offense, as a result of mental disease or defect, the mind of the actor was affected to such an extent that:

a. The defendant was unable to perceive the nature and quality of the act with which he or she is charged; or
b. The defendant was unable to tell right from wrong with reference to the particular act charged.

2. The defense of insanity must be established by a preponderance of the evidence.

The insanity defense is not that frequently pled; one study of eight states showed that it was used in less than 1 percent of all criminal cases. Also, according to the same study, when the insanity defense was raised, it was successful only 26 percent of the time.⁹

Because the defense pled Dearbone not guilty by reason of insanity, there were two possible verdicts. If the jury found Dearbone guilty, he would be sentenced for the crime charged, which was first-degree premeditated murder. If he were acquitted by reason of...