Note: This blog post originally appeared on the National ACLU Blog of Rights. That post can be found here.

By Anna Arceneaux, Staff Attorney, ACLU Capital Punishment Project

(Update: John Ferguson was executed at 6:17 PM E.T. on Monday, August 5th)

Unless the United States Supreme Court intervenes in the next few days, Florida will execute John Ferguson on August 5, despite a well-documented history of his psychosis spanning over 40 years.

Diagnosed with paranoid schizophrenia, Ferguson believes that he is the "Prince of God" and that after his execution he will be reincarnated in his same body, help Jesus fight the Antichrist, save America from a communist plot, and rule the earth.

He thinks his conviction is the result of a communist conspiracy. He is certain that the state seeks to execute him not for his crimes but to prevent him from ascending to sit at God's right hand.

After a traumatic brain injury at age 21, Ferguson spent a decade in and out of mental hospitals. Doctors recommended that he receive long-term hospitalization and treatment. They warned that he should remain hospitalized because he was dangerously mentally ill. Nevertheless, he was ultimately discharged. Within two years, Ferguson was facing trial for multiple murders.

Ferguson's trial attorneys never told his jurors about his mental illness. He has spent 35 years on Florida's death row, and not surprisingly, he continues to suffer from mental illness, including the same hallucinations and delusions that plagued him before his arrests.

Even the Florida Supreme Court agrees that Ferguson is severely mentally ill and suffers from paranoid schizophrenia. But the court ruled that Ferguson's execution could proceed because they applied the wrong legal standard for the mental competency required to be executed. Then, favoring finality over well-established constitutional law, the federal Court of Appeals for the Eleventh Circuit deferred to the Florida Supreme Court's ruling, even though a judge on the panel recognized that it had applied a "patently incorrect" legal standard.

Ferguson's attorneys have now filed a petition in the U.S. Supreme Court, asking the Court to review his case. Constitutional law is unambiguous: killing the insane violates the Eighth Amendment's ban on cruel and unusual punishment. A condemned prisoner must have a rational understanding of the reason for his execution and the effect of his execution before the state puts him to death. Ferguson has neither.

Despite the constitutional prohibition, states across the country continue to execute the mentally ill (such as Edwin Hart Turner, killed last year by the state of Mississippi). Florida will continue the trend on Monday, if the U.S. Supreme Court does not intervene.

Florida is one of the country's leaders in death sentences and executions. Ferguson's execution would be another grave injustice on the state's long list. The Supreme Court must step in before Florida executes a man who is severely mentally ill.

To learn more about mental illness and the death penalty, go here.

Take Action, call on Governor Scott to intervene in Ferguson’s execution!