CHICAGO (Reuters) – Missouri Governor Eric Greitens halted the execution of a man scheduled to be put to death on Tuesday for killing a woman during a burglary after his attorneys argued that recent DNA evidence showed he is innocent.

Greitens issued the stay of execution for Marcellus Williams, 48, just over four hours before he was scheduled to die by lethal injection in a Bonne Terre state prison for the stabbing death of former St. Louis Post-Dispatch reporter Felicia Gayle during an August 1998 robbery at her home.

Greitens said in a statement he would appoint a Board of Inquiry to examine the new DNA evidence and recommend whether he should commute Williams’ death sentence.

The stay came as opposition to the execution mounted. More than 200,000 people had signed an online petition asking Greitens to intervene, and a rally protesting the execution was planned in St. Louis later on Tuesday, featuring speakers such as the head of the Missouri NAACP.

“The DNA evidence says he’s innocent,” Kent Gipson, Williams’ attorney, said earlier on Tuesday.

Williams was sentenced to death in 2001 after prosecutors said he stabbed Gayle 43 times when she surprised him as he was burglarizing her home.

Gipson had also petitioned the U.S. Supreme Court to halt the execution, arguing that recent DNA analyses using newer methods found that DNA on the knife was from an unknown male, not Williams.

Hairs found on Gayle’s body also exclude Williams, said forensic DNA expert Greg Hampikian, who was hired by Williams’ attorneys and has examined the DNA evidence.

Missouri’s Supreme Court delayed Williams’ execution in 2015 to allow for the new testing, but denied a petition to halt it with no explanation after the results were made available, Hampikian said.

Earlier in the day on Tuesday, Missouri Attorney General Josh Hawley’s office said it remained confident that Williams is guilty based on non-DNA evidence.

The state had previously argued that Williams took property from the house, and that two witnesses said he confessed to the crime. Defense attorneys argued that the witnesses, including a former cellmate, were motivated by a reward.

“Despite the violent and bloody nature of the crime scene, police failed to uncover any forensic evidence connecting petitioner to the murder,” Williams’ Supreme Court appeal said.

According to the Post-Dispatch, Gayle, known as Lisha, worked there as a reporter from 1981 to 1992, before leaving the paper to do volunteer social work with children and the poor.