Lyndon ? A northeast Kansas jury will decide whether to recommend a death sentence for a man convicted of killing his estranged wife and three other family members after his attorneys failed to convince jurors he was too mentally ill at the time to be held legally responsible for the killings.

James Kraig Kahler’s trial highlighted the state’s unusual rule for determining when a mental illness or defect warrants a criminal defendant’s acquittal. Some legal scholars believe it’s more difficult in Kansas than in most other states for a defendant to prevail after making mental illness an issue, raising questions about the constitutionality of the state’s standard.

The jury in Kahler’s case in Osage County District Court expected to hear additional evidence Monday, before considering whether he should be executed by lethal injection or serve life in prison without the possibility of parole. District Judge Phillip Fromme must sign off if jurors recommend death.

The jury’s seven men and five women convicted Kahler last week of shooting his wife, their two teenage daughters and the wife’s grandmother the Saturday evening after Thanksgiving 2009 in the grandmother’s home just outside Burlingame, a small town 20 miles south of Topeka. His wife was having a lesbian affair and pursuing a divorce.

Pressures at home

Defense attorneys contend he was severely depressed and snapped under the strain of his crumbling family and professional lives. Kahler, 48, a former city utilities director in Weatherford, Texas, and Columbia, Mo., had lost the latter job after his deteriorating mental health caused his work to suffer, and he moved back to Kansas just weeks before the killings to live with his parents outside Topeka.

Under Kansas law, Kahler’s mental illness was a defense only if it prevented him from forming the intent to kill or acting with premeditation. Prosecutors presented evidence showing he had been upset with each of the victims and targeted them one by one, never missing a shot.

Defense attorney Thomas Haney said Kansas’ legal standard on mental illness, in place since 1996, probably will be an issue in an appeal. Haney noted that Topeka once was home to the famed Menninger clinic; a founder, Dr. Karl Menninger, was credited with bringing psychiatry into the mainstream of American life before he died in 1990.

“One would think being at the heart of advanced medical care — with Menninger — we’d be a little more progressive,” Haney said after the verdict. “We’re one of the least progressive.”

But the state’s standard has defenders. Kansas House Speaker Mike O’Neal, a Hutchinson Republican who helped draft the 1995 legislation imposing it, said allowing defendants to plead not guilty because of insanity allowed them to escape responsibility and prison time if defense attorneys had a psychiatrist use “magic words” about the accused’s mental state during testimony.

“Our thinking at the time was that pleading insanity was a huge loophole,” O’Neal said. “The concept was, can we tighten this up?”

The victims of the shootings were Karen Kahler, 44; her grandmother, Dorothy Wight, 89; and the Kahlers’ daughters, Emily, 18, and Lauren, 16. Kraig and Karen Kahler’s son, Sean, now 12, was at the scene but wasn’t threatened and escaped without physical injuries.

According to testimony during Kahler’s trial, Karen Kahler began having a sexual relationship with a Weatherford, Texas, woman in 2008, just before the family moved to Columbia, Mo. She filed for divorce in January 2009, and according to testimony, Kraig Kahler believed his daughters had sided with their mother. Also, he was said to believe Wight had a duty to push Karen Kahler to stay in the marriage.

A psychiatrist testified for the defense that Kahler was severely depressed and lost the ability to control his behavior.

Varying standards

In half of the states, including those bordering Kansas, the basic issue in an insanity defense is whether a defendant was so impaired by a mental illness or defect that he couldn’t understand his alleged conduct was criminal, according to the FindLaw.com website. The rule, which used to apply in Kansas, dates to 1840s England.

Twenty others adopted a standard developed by the American Law Institute in the 1960s that a defendant “lacks substantial capacity” to appreciate the criminal nature of his conduct or keep his behavior within the law. New Hampshire says a defendant is not criminally responsible if his act is the product of a mental illness or defect.

Idaho, Montana and Utah also have abolished the insanity defense, though they allow defendants to plead guilty but insane or mentally ill, while Kansas does not.

“This would be a perfect case to challenge Kansas’ approach to mental illness in a criminal case,” said Christopher Slobogin, a professor of both law and psychiatry at Vanderbilt University.

But O’Neal and others question whether a challenge would be successful.

In 1994, the U.S. Supreme Court refused to hear a challenge to Montana’s abolition of the insanity defense, a move interpreted as allowing all states to follow suit. In a 2006 ruling in an Arizona case, a majority of the nation’s highest court indicated that states had broad discretion in how they treated mental illness in criminal cases.

“The U.S. Supreme Court has never held that you have to have an insanity defense,” said Jeffrey Jackson, a law professor at Washburn University in Topeka.