(CNN) Kevin Johnson -- a death row inmate who was convicted in the 2005 murder of a Kirkwood, Missouri, police officer but claimed racial bias in his prosecution -- was executed Tuesday night by lethal injection.
Johnson, 37, was pronounced dead at 7:40 p.m. CT. He didn't give a final statement, according to Missouri Department of Corrections spokesperson Karen Pojmann.
Johnson's execution came soon after the US Supreme Court denied his request for a stay of execution; Justices Ketanji Brown Jackson and Sonia Sotomayor dissented, according to the court's website. A day earlier, the Missouri Supreme Court had similarly denied Johnson's request for a stay after Johnson and his attorneys argued racial discrimination played a role in his prosecution.
Mary McEntee, the widow of Kirkwood Police Sgt. William McEntee, said her husband was killed on his hands and knees in front of people he dedicated his life to serve.
"When he left for work that day, we could not imagine that he would be executed by someone he gave his life to protect," she said at a media briefing Tuesday evening. "Bill didn't get to fight for his life. He didn't have the chance to be heard before a jury, to decide whether he would live or die."
She also thanked the prosecutors who put in the "hard work and endless hours ... for justice for Bill."
The execution was not witnessed by Johnson's 19-year-old daughter, who had failed this month to get a federal court to prevent the state from executing her father unless she was permitted to be a witness. Missouri law bars people younger than 21 from witnessing the proceeding.
Pojmann said Johnson met with his daughter earlier Tuesday.
On Monday, the Missouri Supreme Court heard arguments in two requests for a stay in Johnson's case: one by Johnson, who was Black, and the other by a special prosecutor appointed at the request of the St. Louis County Prosecuting Attorney's Office, which secured Johnson's conviction on a first-degree murder charge and death sentence for the murder of McEntee.
Both requests sought a stay so claims of racial prejudice could be heard by the St. Louis County Circuit Court, which previously denied a motion by the special prosecutor to vacate Johnson's conviction, saying there was not enough time before Johnson's scheduled execution to hold a hearing.
In their motion, attorneys for Johnson pointed to "long-standing and pervasive racial bias" in St. Louis County prosecutors' "handling of this case and other death-eligible prosecutions, including the office's decisions of which offense to charge, which penalty to seek, and which jurors to strike."
Per their request, the prosecuting attorney sought the death penalty against four of five defendants tried for the killing of a police officer while in office -- all of them Black, while the fifth was White. In the case with a White defendant, Johnson's request says, the prosecutor invited defense attorneys to submit mitigation evidence that might persuade the office not to seek death -- an opportunity not afforded the Black defendants.
Additionally, they pointed to a study by a University of North Carolina political scientist of 408 death-eligible homicide prosecutions during this prosecutor's tenure that found the office largely sought the death penalty when the victims were White.
Those claims appeared to be supported by a special prosecutor, who was appointed to the case last month after the St. Louis Prosecuting Attorney's Office cited a conflict of interest. The special prosecutor, Edward E.E. Keenan, similarly "determined that racist prosecution techniques infected Mr. Johnson's conviction and death sentence," he wrote in his own request for a stay.
The special prosecutor found "clear and convincing evidence of racial bias by the trial prosecutor," he wrote in the request, citing similar evidence to that listed by Johnson's attorneys in their request for a stay.
The Missouri Attorney General's Office argued against a stay, saying the claims were without merit. The special prosecutor's "unproven claims," the AG's office said in a brief, do not amount to a concession of wrongdoing by the state, which stands by the conviction.
"The McEntee family has waited long enough for justice," the brief said, "and every day longer that they must wait is a day they are denied the chance to finally make peace with their loss."
Bob McCulloch, the longtime St. Louis prosecuting attorney who was voted out of office in 2018 after 27 years, has denied he treated Black and White defendants differently.
"Show me a similar case where the victim was Black and I didn't ask for death," he was quoted as saying by St. Louis Public Radio earlier this month about his time in office. "And then we have something to talk about. But that case just doesn't exist."
In its ruling denying Johnson's request for a stay, the Missouri Supreme Court wrote Monday, "There simply is nothing here that Johnson has not raised (and that this Court has not rejected) before and, even if there were, Johnson offers no basis for raising any new or re-packaged versions of these oft-rejected claims at this late date."
A defense attorney for Johnson decried Monday's state Supreme Court ruling as a "complete disregard for the law in this case."
"The Prosecutor in this case had requested that the Court stop the execution based on the compelling evidence he uncovered this past month establishing that Mr. Johnson was sentenced to death because he is Black," lawyer Shawn Nolan said in a statement. "The Missouri Supreme Court unconscionably refused to simply pause Mr. Johnson's execution date so that the Prosecutor could present this evidence to the lower court, who refused to consider it in the first instance given the press of time."
Johnson's attorneys then asked the nation's highest court for relief, and the Court declined to step in.
In an opinion released Wednesday night -- in which Justice Jackson wrote that "one day later" she wanted to explain her vote to grant Johnson's request -- Jackson said she thought there was a "likelihood" that Johnson would have succeeded on the merits of his federal due process claim.
"And it was clear that he would (and obviously did) suffer irreparable harm absent a stay," she wrote.
Johnson's case qualified as one of those "rare" instances, Jackson wrote, when a "litigant can credibly claim that a State's erroneous interpretation of, or refusal to comply with, its own law can amount to a federal due process violation."
She charged that the Missouri Supreme Court had skipped over critical steps in its evaluation of the case, that she said amounted to a likely violation of the inmate's rights under the 14th Amendment.
"In short, a State cannot provide a process for postconviction review," Jackson wrote, "and then arbitrarily refuse to follow the prescribed procedures."
Gov. Mike Parson, a Republican, also on Monday denied a request for clemency from Johnson's attorneys.
"Mr. Johnson has received every protection afforded by the Missouri and United States Constitutions, and Mr. Johnson's conviction and sentence remain for his horrendous and callous crime," Parson said in a statement. "The State of Missouri will carry out Mr. Johnson's sentence according to the Court's order and deliver justice."
Johnson was sentenced to die for the July 5, 2005, murder of McEntee, 43, who was called to Johnson's neighborhood in response to a report of fireworks.
Earlier that day, Johnson's 12-year-old brother had died after having a seizure at their family's home, according to court records. Police were there at the time of the seizure, seeking to serve a warrant against Johnson, then 19, for a probation violation.
Johnson blamed the police, including McEntee, for his brother's death. And when McEntee returned to the neighborhood later that day, Johnson approached the sergeant's patrol car, accused him of killing his brother and opened fire.
He left behind a wife, a daughter and two sons, according to the Officer Down Memorial Page.