With one exception, executions in Kentucky will not be possible until next year.Governor Steve Beshear was recently asked to sign three death warrants. He signed one, but held off on two others, citing a shortage of Sodium thiopental (Pentathol), which is used in lethal injection executions.Gregory L. Wilson is scheduled to be put to death on September 16th with the state's last usable dose. Justice Cabinet Secretary J. Michael Brown says Pentathol expires quickly once it's mixed into the lethal injection cocktail. And the state would have to take unusual steps to perform any other executions before a new shipment arrives next year."I don't want to say it would've been impossible, but the only way to do it to would to have been able to do almost do back to back executions on the same date, and I don't think that's anything that was ever considered," he says.This would be the first execution in Kentucky since the state Supreme Court ruled that the lethal injection protocol must be readopted to be legal. At least two lawsuits challenge the protocol. One was filed by Wilson and is pending. A judge has not yet ruled on the other. Attorney General's spokesperson Allison Gardner Martin says executions can continue in the commonwealth."We believe that the rulings that have been passed by the U.S. Supreme Court, we believe the U.S. Supreme Court has upheld Kentucky's lethal injection protocol," she says.The last execution in Kentucky was in November 2008.