(CNN) -- Scott Panetti dressed in a purple cowboy outfit and called Jesus, John F. Kennedy and the Pope to the stand in his trial for the 1992 slayings of his mother and father-in-law.
He was convicted of shooting them to death at close range, in front of his wife and daughter.
At 6 p.m. Wednesday, Texas is set to execute the 56-year-old, bringing to an end a case that has for years sparked debate over whether the state can execute someone who is severely mentally ill.
Panetti has suffered from schizophrenia for 30 years, his lawyers say, and he was hospitalized for mental illness numerous times before the murders.
Attorney asks governor for stayThough Panetti received initial evaluations of his mental health, his state of mind has deteriorated, his lawyer Kathryn Kase said. She noted in a letter to Texas Gov. Rick Perry that Panetti hasn't received a mental evaluation in seven years. Perry should grant a 30-day stay to the scheduled execution so that that an evaluation can be done to determine if he understands his punishment.
It's not just Panetti's legal team that believes his execution would be a violation of the Constitution's prohibition of cruel and unusual punishment. Mental health professionals and advocates, members of the American Bar Association and representatives from the European Union have urged that he be spared.
More than a dozen conservative leaders -- including a Washington Times opinion editor and a Ronald Reagan biographer -- have also written to Perry, asking that Panetti's execution be halted and his sentence be commuted to life in prison.
'Rather than serving as a measured response to murder, the execution of Mr. Panetti would only serve to undermine the public's faith in a fair and moral justice system,' their letter reads.
Ex-wife: He should never have stood trialAs a recent CNN opinion piece noted, Sonja Alvarado, Panetti's ex-wife wife and the daughter of his victims, filed a petition stating that because of Panetti's paranoid delusions when he committed the killings, he never should have faced trial.
Opinion: The atrocity of killing a mentally ill man
'If he's executed there should be a sense of outrage,' said Ron Honberg, legal director for the National Alliance on Mental Illness. 'There's no question he's mentally ill. If this happens, the message would be -- 'we just don't care.'
'To execute him flies in the face of even supporters of the death penalty who say that it should be carried out with inmates who are the worst of the worst,' Honberg continued. 'It would be much more compassionate and practical to spend money treating inmates with mental illness rather than execute this man.'
Clemency deniedThe Texas Board of Pardons and Parole voted 7-0 to deny clemency.
There are appeals before the U.S. Supreme Court and the U.S. Fifth Circuit Court of Appeals.
Panetti would be the 11th person Texas officials have executed in 2014.
Columbia University psychiatry professor and American Psychiatric Association member Dr. Paul Appelbaum said that he's followed the case since 2007, when the U.S. Supreme Court stopped Panetti's execution and ruled that another competency review be performed.
The Fifth Circuit found in 2013 that Panetti was competent enough to be executed.
Lately, American society has been engaged in a conversation about mental illness and the role of the death penalty for inmates who are not of sound mind, Appelbaum told CNN.
'We've come to understand that there is no legitimate penal reason to put such a person to death,' he said. 'It's not likely to deter people from committing crimes and given Panetti's impairment, it's not a fitting punishment.'
Death penalty fast facts Entities 0 Name: Panetti Count: 12 1 Name: Texas Count: 3 2 Name: Perry Count: 2 3 Name: U.S. Supreme Court Count: 2 4 Name: CNN Count: 2 5 Name: Honberg Count: 1 6 Name: Ron Honberg Count: 1 7 Name: Ronald Reagan Count: 1 8 Name: National Alliance on Mental Illness Count: 1 9 Name: Kathryn Kase Count: 1 10 Name: American Psychiatric Association Count: 1 11 Name: Columbia University Count: 1 12 Name: Texas Board of Pardons Count: 1 13 Name: John F. Kennedy Count: 1 14 Name: Scott Panetti Count: 1 15 Name: Washington Times Count: 1 16 Name: Sonja Alvarado Count: 1 17 Name: American Count: 1 18 Name: Fifth Circuit Count: 1 19 Name: European Union Count: 1 20 Name: U.S. Fifth Circuit Court of Appeals Count: 1 21 Name: Appelbaum Count: 1 22 Name: American Bar Association Count: 1 23 Name: Rick Perry Count: 1 24 Name: Jesus Count: 1 25 Name: Dr. Paul Appelbaum Count: 1 Related 0 Url: http://ift.tt/1yfaNnU Title: Texas to execute mentally ill defendant, sparks debate Description: AUSTIN -- Scott Panetti dressed as a cowboy during his murder trial and, acting as his own lawyer, called John F. Kennedy, Jesus and the Pope as witnesses. He's been hospitalized more than a dozen times for psychosis and delusions.
