In November, the United States Supreme Court will hear a case that might shock even those familiar with Texas' reputation for being hawkish when it comes to capital punishment. Although the court outlawed execution of the mentally incompetent in 2002, Texas has continued to use the murky legal definitions of sanity and disability to execute mentally ill prisoners.

At the center of the upcoming "Moore versus Texas" is not only the state's reliance on outdated medical parameters, but the use of the so-called "Lennie Standard." This is the name Texas Court of Criminal Appeals Judge Cathy Cochran gave "an unscientific seven-pronged test … based on the character Lennie Smalls from John Steinbeck's 'Of Mice and Men,'" according to the Death Penalty Information Center.

In Steinbeck's 1937 novel, Lennie is the large, mentally disabled farmhand who serves as the protagonist's constant companion. The climax of the novel hinges on Lennie's unwitting murder of a woman as he goes to stroke her hair, unaware of his own strength.

The "Lennie Standard" asks questions such as whether a defendant showed forethought or an ability to act deceptively as determiners of mental competency.

'Borderline intellectual functioning'

In the case now before the Supreme Court, the state of Texas has argued that Bobby James Moore was mentally fit because he employed the use of a wig and hid his weapon during the armed robbery of a grocery store that ended in the death of the store's owner, Jim McCarble, in 1980. This is despite the fact that, according to a piece from Adam Liptak of the New York Times, Moore "reached his teenager years without understanding how to tell time" and had a psychiatrist testify on his behalf that he "suffers from borderline intellectual functioning."

Political deadlock in Washington has left the Supreme Court down one justice, which will affect the outcome of trials like Moore v. Texas

Liptak, who follows the Supreme Court for the Times, told DW that the source of the conundrum was in no small part due to the court "allowing states, within broad limits, the ability to decide for themselves who was and wasn't mentally disabled … bringing about Texas' use of this, shall we say, unusual system."

This is what led Cochran to come up with the "Lennie Standard" in 2003 after the state legislature failed to provide adequate parameters.

The definition dilemma

The case highlights not only the Lone Star State's history of executing mentally ill patients - for example, Andre Thomas, a man who removed one of his eyes with his own hands and ate it, still sits on death row - but also the legal conundrum of defining disability. There is no X-ray that reveals mental illness, and the Supreme Court ruled in 2014 that relying solely on a low IQ, a system which was employed by the state of Florida, was not a solid enough legal basis to rule someone incompetent.

Even the Diagnostic and Statistical Manual of Mental Illness (DSM), the gold standard for defining mental disability put out every few years by the American Psychiatric Association, is subject to the changing interpretations of medicine's perhaps most inexact branch.

The novelist Steinbeck's son Thomas had some very cutting words for the Texas Court of Criminal Appeals, saying in 2012 that "I find the whole premise to be insulting, outrageous, ridiculous and profoundly tragic … I am certain that if my father, John Steinbeck, were here, he would be deeply angry and ashamed."

Nobel Prize winner John Steinbeck one said Lennie was based on a real ranch hand who was treated with leniency

Supreme Court 'unlikely to accept Texas standard'

Liptak, however, saw reason to believe the "Lennie Standard" will be struck down. "If the Supreme Court wasn't willing to accept the Florida standard based on a hard number, they are unlikely to accept the Texas standard."

He said, though, that this would likely have more to do with the state's out-of-date medical criterion than "Of Mice and Men."

"In general, the trend at the Court is to cut back on the death penalty," Liptak added, though a nationwide ban is unlikely to follow, particularly in the face of staunch public support for the practice in states like Texas.

Capital punishment in Texas accounts for about one third of the national total, the state having executed 538 inmates since the US brought back the death penalty in 1976.