In a press release, Fallin said: “Last minute questions were raised today about Oklahoma’s execution protocol and the chemicals used for lethal injection. “After consulting with the attorney general and the Department of Corrections, I have issued a 37 day stay of execution while the state addresses those questions and ensures it is complying fully with the protocols approved by the United States Supreme Court.”

In a terse statement to reporters, DOC Director Robert Patton said he had visited with the family of Barry Van Treese.

Glossip was convicted of first-degree murder in the 1997 killing of Van Treese, who owned the Oklahoma City motel where Glossip worked. Van Treese was beaten to death with a baseball bat by Justin Sneed, who testified Glossip paid him to carry out the killing.

Patton announced the execution couldn’t begin as planned, but said little else before rushing out of the room without taking questions. A spokeswoman said she hoped to have more information soon on the drug mixup.

Oklahoma changed its protocol in the wake of the April 2014 botched execution of Clayton Lockett, in which an IV was improperly inserted. Lockett died on the gurney 43 minutes after his execution began.

The state’s announcement it had received potassium acetate instead of potassium chloride raised questions about when prison officials knew they had the wrong drug.

The revamped protocol requires the death row unit section chief to do the following: “Ensure the chemicals are ordered, arrive as scheduled and are properly stored. The chemicals shall be under the direct control of the H Unit Section Chief and stored in a secured, locked area and monitored to ensure compliance with manufacturer specifications.”

David Kroll, a pharmacologist and medical writer, said the drugs are “two different chemicals.” But they would function similarly to stop the heart, he said.

“They are roughly equally toxic to rodents,” Kroll said.

For medical use, the two drugs are interchangeable “but we don’t do these experiments on people.”

The similarities between the drugs raises the question of whether the state simply couldn’t obtain potassium chloride, which is part of its protocol, and substituted potassium acetate. Prison officials notified Glossip’s attorneys in August they would use the three-drug combination that includes potassium chloride.

Prison officials said Wednesday that two other executions scheduled for October were still scheduled to take place. Benjamin Cole is scheduled to be executed Oct. 7, while John Marion Grant is set to die Oct. 28.

Dale Baich, the attorney who represented Glossip and other death row inmates in a challenge to Oklahoma’s lethal injection drug protocol, said state officials had not told attorneys they planned to use a different drug from potassium chloride.

“This is the same state which took over 40 minutes to kill Clayton Lockett, using a similar three-drug protocol that was to be used today. Today’s hastily abandoned plans show what happens when states carry out executions in secrecy with unqualified execution team members and no public oversight.”

When asked if he trusted the Department of Corrections to fully investigate the drug mixup, Baich said he had no comment.

“Oklahoma once again realized something was wrong. Oklahoma has had months to prepare for this execution, and today’s events only highlight how more transparency and public oversight in executions is sorely needed,” he said.

The fact that Glossip’s execution was stayed 37 days — an unusual number — was not explained. However, the Nov. 6 date is after a new state law takes effect allowing inmates to be put to death with nitrogen gas if other methods are unavailable.

Ziva Branstter, Cary Aspinwall and Shane Bevel are journalists from The Frontier, a Tulsa-based online publication.