A man convicted of the rape and murder of a nine-year-old girl is to be executed in the midwestern US state of Missouri on Tuesday.
Christopher Collings, 49, is to be put to death by lethal injection at 6:00 pm Central Time (0000 GMT) at the state prison in Bonne Terre.
Collings was convicted of the November 2007 murder of Rowan Ford, the stepdaughter of a friend, in the rural town of Stella.
Her body was dumped in a sinkhole and found several days later.
Collings's lawyers had asked the Supreme Court for a last-minute stay of execution but it was denied.
They argued that the police chief, who obtained Collings's confession and was the primary witness at his trial, had a troubled history and lacked credibility.
In addition, they said, the girl's stepfather, David Spears, confessed to involvement in the girl's death but did not face murder charges.
Missouri Governor Mike Parson denied a clemency request from Collings, clearing the way for his execution.
"Mr. Collings has received every protection afforded by the Missouri and United States Constitutions, and Mr. Collings's conviction and sentence remain for his horrendous and callous crime," Parson said.
"There is not and never has been any doubt about Collings's involvement or the heinousness of his crimes."
There have been 22 executions in the United States this year including three in Missouri.
The death penalty has been abolished in 23 of the 50 US states, while six others -- Arizona, California, Ohio, Oregon, Pennsylvania and Tennessee -- have moratoriums in place.