Jurors in the Daniel Mustard trial this week began considering his level of guilt in the murder of his 87-year-old neighbor, Ruby Andrews, in her Manchester home on April 5, 2009.

The three-week old trial was expected to conclude this week in Kitsap County Superior Court with final arguments on both sides, followed by jury deliberations.

In theory, the panel could find Mustard innocent for any of three reasons.

Either they could feel insufficiently convinced Mustard killed Andrews, or they could shield him from a guilty verdict through an insanity or diminished-capacity defense.

Mustard’s lawyer, Bryan Hershman, focused on the mental defenses rather than trying to argue that Mustard didn’t commit the murder.

And incriminating evidence against the teen includes cell phone pictures of Andrews’ body after the murder and blood on his shoes, as well as testimony from his friends saying he described the murder to them.

Still, the court’s instructions to the jury were specific.

“The defense of insanity,” Judge Leila Mills advised the jury, “does not remove from your consideration the question of whether the defendant actually committed the act charged. You should not consider the defense of insanity unless you first find, beyond a reasonable doubt, that the defendant committed the act charged.”

If the jury decides Mustard killed Andrews, the members will then need to determine whether he had enough of a moral compass, at the time, to hold him responsible for the murder.

The teen wouldn’t meet the legal standard of culpability for the crime if he didn’t have the ability to form “intent” or he didn’t “act intentionally” when he killed Andrews.

If he didn’t intentionally kill Andrews, he would be innocent due to his diminished capacity at the time.

“A person acts with intent or intentionally,” Mills wrote in her instructions, “when he or she acts with the objective or purpose to accomplish a result which constitutes a crime,” according to the court’s instructions to the jury.

“If you conclude,” she said, “that due to mental illness, mental disorder, involuntary intoxication, or any combination of these factors, Mr. Mustard was unable to form the intent to commit any of the crimes charged, it will be your duty to return a verdict of not guilty for those crimes for which you find Mr. Mustard was unable to form the necessary intent.”

Or the jury could find Mustard innocent due to insanity.

For a defendant to be found not guilty by reason of insanity, the jury must find that, as a result of mental disease or defect, the defendant’s mind was affected to such an extent that the defendant was unable to: (1) perceive the nature and quality of the acts with which the defendant is charged; (2) was unable to tell right from wrong with reference to the particular acts with which the defendant is charged, according to the court’s instructions to the jury.

Throughout the trial, the lawyers debated about the definition of “nature and quality” in the definition of insanity.

“The concept of appreciation of nature and quality means more than intellectual knowledge and requires an awareness of the significance of the act,” according to the defendant’s supplemental instructions to the jury. “An individual may intellectually know his actions are wrong, but mental disease or defect may render that individual unaware of the moral significance of his actions.”

Mustard also should be considered legally insane if he involuntarily entered into an altered state of mind due to taking the dose of drugs prescribed by his doctor.

“A condition of mind that is proximately induced by the voluntary act of a person charged with a crime does not constitute insanity,” according to the defendant’s supplemental instructions to the jury. “However, intoxication is involuntary if it arises from medical advice and includes the use of medicinal drugs, including intoxication resulting from a physician’s prescription of an intoxicating dose.”

That issue could factor into the case since Mustard may have killed Andrews during a mania induced by anti-depressants and other drugs prescribed by his doctors, according to testimony from nationally known forensic psychiatrist Park Dietz.