An 11th hour attempt to stop the execution of Kevin Johnson was put into motion Tuesday by his attorneys, who are seeking intervention by the U.S. Supreme Court.
The 37 year old's execution is scheduled for 6 p.m.
The application for stay of execution alleges Johnson's case "was unconstitutionally tainted by racial discrimination."
"The State of Missouri is poised to execute Kevin Johnson, not for his crimes, but because he is Black and his victim was White," assistant federal defender Joseph Luby wrote.
In July 2005, Johnson fired several shots at Sgt. William McEntee, a white Kirkwood Police Department officer. McEntee, a father of three, died.
Johnson was convicted of first-degree murder and sentenced to death during his second trial.
On Monday afternoon, special prosecutor E.E. Keenan argued before the Missouri Supreme Court that former St. Louis County prosecutor Robert McCulloch - whose father was killed in the line of duty - sought the death penalty in four out of five cases involving a police officer death during his career. All four of those defendants were Black. The fifth was white and Keenan alleged that suspect's conduct "was more aggravated."
In court documents, Keenan also said McCulloch intentionally eliminated Black jurors during Johnson's second trial.
Luby notes that the claims of discrimination were not brought by Johnson, but by a special prosecutor. Keenan was appointed by St. Louis Circuit Court to review the case.
Late Monday, the Missouri Supreme Court denied the motion to stay in a 5-2 ruling.
The application submitted Tuesday requests the high court halt the execution so the state Supreme Court can review the special prosecutor's claims. McCulloch refused to speak during the special prosecutor's investigation, according to court documents.
The Missouri Attorney General's Office has argued the execution should go forward.
"The McEntee family has waited long enough for justice," the AG' office said in a court filing.
In a response Tuesday, the attorney general's office said Johnson's request "is a transparent refusal to accept moral responsibility for his crimes," and refuted claims of racism as "completely baseless."