Missouri Gov. Jay Nixon on Friday spared the life of a death row inmate four days before the scheduled execution, saying he did so after "significant consideration" of the circumstances but without explaining further.

The death sentence for Kimber Edwards, who had been scheduled to die Tuesday for the contract killing of his ex-wife in suburban St. Louis in 2000, was commuted to life in prison without the possibility of parole.

Nixon said in a statement that he remains convinced that evidence supports Edwards' first-degree murder conviction.

"At the same time, however, I am using my authority under the Missouri Constitution to commute Edwards' sentence to life without the possibility of parole," the Democratic governor said. "This is a step not taken lightly, and only after significant consideration of the totality of the circumstances. With this decision, Kimber Edwards will remain in prison for the remainder of his life for this murder."

It was the second time Nixon has commuted a death sentence to life in prison, the last one in 2011. But Nixon's statement did not give an explanation for his decision, and spokesman Scott Holste declined further comment.

It also was the second U.S. execution halted this week. On Wednesday, a stay of execution was granted for Oklahoma inmate Richard Glossip amid questions about one of the drugs that would have been used in his lethal injection.

Prosecutors said Edwards, now 51, hired Orthell Wilson to kill Kimberly Cantrell because Edwards didn't want to have to pay child support. Wilson was sentenced to life in prison without parole after a plea deal in which he agreed to cooperate against Edwards.

Both men initially confessed, but Edwards and his supporters noted this week that Wilson said in an affidavit this May that he was trying to save himself from the death penalty when he cooperated against Edwards.

Wilson said he was "coerced by police to implicate Edwards" by threat of the death penalty, and that he acted alone.

Edwards' attorney, Jeremy Weis, said Wilson and Cantrell were in a relationship and he killed her after an argument. Meanwhile, Edwards has recanted his confession.

"The argument we made was there is a real question as to Kimber's innocence in this case and I think he took that seriously," Weis said of the governor's decision.

Edwards' daughter, DeAndra Hughes, called her father after hearing the news.

"I was just screaming and he was laughing, just so very relieved," Hughes said. "We are just so happy that Gov. Nixon took the time to review the case and that he came to this decision."

In an interview Thursday with The Associated Press, Edwards said he was coerced into confessing when police threatened to charge the woman he married after divorcing Cantrell and take away their children.

"If they dangle your wife and children over a cliff and tell you they're going to drop them, you're going to do whatever you have to do to save them," Edwards said in a phone interview.

Chuck Cantrell, the victim's brother, said he was disappointed that Nixon did not reach out to the family until moments before announcing his decision.

"In commuting the sentence of a man that facilitated the murder of my sister Kimberly Cantrell, the governor has dishonored her, he dishonored the judicial system with this decision, he dishonored my family with this decision and he dishonored his office with this decision," Cantrell told the AP in an email.

Edwards and Kimberly Cantrell had divorced in 1990, with Cantrell taking custody of their daughter, Erica. In early 2000, Edwards was charged for failing to pay child support.

Erica stayed with her father for three weeks prior to an Aug. 25 hearing, but became concerned when she did not hear from her mother by Aug. 23. She called her aunt, who went to Cantrell's home in University City and found the body. Cantrell, 35, had been shot twice in the head the day before.

Wilson, a tenant in a rental property owned by Edwards, was arrested and pleaded guilty to first-degree murder. Police said Edwards admitted to paying a man $1,600 for the contract killing.