If Jared Lee Loughner's defense attorney, Judy Clarke, decides on an insanity plea, many experts believe it will fail. The burden of proof that the defense bears in such cases has grown in recent years.
No sooner had Jared Lee Loughner appeared in federal court on Jan. 9 to be charged with the attempted assassination a day earlier of Rep. Gabrielle Giffords in Tucson than speculation began to swirl about the nature of his defense. Would he plead not guilty by reason of insanity? And how strong would his case be?
Photographs of the smirking suspect with his head freshly shaved, reports of his angry and at times incoherent postings on the Internet, and the accounts of former classmates and longtime friends all fed the notion that Mr. Loughner was, in layman's terms, unstable and possibly deeply disturbed.
At the same time, as investigators retraced Loughner's steps before the shooting - which gravely wounded Ms. Giffords and claimed the lives of six others -a narrative emerged indicating that the 22 year old had methodically and deliberately planned the attack.
On Wednesday a federal grand jury officially indicted Loughner for the attempted assassination of Giffords and two of her aides. Further federal and state charges likely are forthcoming. He has already been charged with the murder of a federal judge, a capital offense.
As the charges multiply, legal analysts are expecting an extended spotlight on the issue of the insanity defense, which, they say, will be extremely difficult to mount successfully.
Loughner's defense attorney is Judy Clarke, who also represented Unabomber Ted Kaczynski in 1998.
"Judy Clarke is one of the most respected capital defense attorneys in the country, and the speculation is that she will likely go for the insanity plea," says Robert Pugsley, professor of law at Southwestern Law School.
The McNaughton rule
Professor Pugsley and others say they will be watching the Loughner trial to see whether or not it advances the McNaughton rule, the longtime standard for insanity in the United States and Britain. The rule is twofold: Does the accused understand the nature of his act? And did he know the act was morally wrong?
The rule is named for a 19th-century British defendant who was acquitted "by reason of insanity." The public backlash to that verdict prompted a stricter legal test for insanity. The burden was placed on the defense to prove to the jury that at the time of the crime, the defendant "was laboring under such a defect of reason, from disease of the mind, as to not know the nature and quality of the act he was doing or, if he did know it, that he did not know what he was doing was wrong."
In the mid-20th century the US standards for determining insanity were temporarily weakened, especially in the 1950s formulation of the so-called Durham rule, in which "an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect."
But the burden on the defense to prove an incapacity to know right from wrong was gradually restored, especially after John Hinckley was found not guilty by reason of insanity in 1982 for the attempted assassination of Ronald Reagan.
Amid a strong public backlash, the defense is used in less than 1 percent of all homicide cases and, of those, is successful only 10 to 25 percent of the time, according to Anita Boss, a Virginia- based forensic psychologist who has testified in scores of insanity defense cases.
'Nearly impossible to win'
"People are polarized about the insanity defense and it has been nearly impossible to win these cases for decades," says J. …