Ernest Johnson has been executed for killing three convenience store workers in a 1994 robbery incident.
He was executed despite claims by his attorney and death penalty opponents that he had an intellectual disability and killing him violated the Constitution.
Ernest Johnson, 61, received a lethal injection on Tuesday at a state prison in Bonne Terre, Missouri.
He was pronounced dead at 6:11 p.m. local time, a spokeswoman for the state department of corrections said.
Pope Francis, two members of Congress and former Democratic governor Bob Holden were among those who spoke out against the execution.
The U.S. Supreme Court denied an application for a stay of execution Tuesday.
In a filing to the high court Tuesday, Johnson’s legal team reiterated IQ tests have indicated he had the intellectual capacity of a child and wrote that there would be “no tangible harm” if his execution was delayed while questions over whether lower courts had “constitutionally considered” his disability were further explored.
“This Court has said states simply cannot execute the intellectually disabled,” Johnson’s attorneys wrote, referring to a 2002 Supreme Court ruling.
Johnson’s execution was the first by Missouri prison officials since May 2020, as the pandemic put a hold on states’ death chamber operations before Texas jump-started the practice this year.
Four relatives of the three people Johnson killed in 1994 were present, the spokeswoman said. A media witness said that Johnson’s breathing became laboured but there were no visible signs of distress.
What Did The Governor Said About Ernest Johnson?
On Monday, Governor Mike Parson announced the state would “deliver justice and carry out the lawful sentence Mr Johnson received in accordance with the Missouri Supreme Court’s order”.
Writing in support of the execution, Attorney General Eric Schmitt said that the facts of Johnson’s actions “plainly reflect the offender’s ability to plan, strategise, calculate, and scheme effectively”.
Ernest Johnson had asked to be executed by firing squad but his request was denied by the Missouri Supreme Court, and he was instead executed by lethal injection.
In a handwritten statement before his death, Johnson apologised for his crimes and thanked his family, friends and lawyer for their support.