Oklahoma’s attorney general has decided that the state will no longer carry out executions, barring them until 2016 as they investigate the use of the wrong drugs in recent executions.

As Vice reports:

The inquiry was launched after the Oklahoma Department of Corrections received potassium acetate for the execution of Richard Gossip in September, instead of potassium chloride – one of the drugs approved to be part of a lethal, three-drug cocktail. Oklahoma’s governor called off Gossip’s execution right before it was to take place upon learning about the mix-up.

The error also occurred during the execution of Charles Warner, according to his autopsy.

For more on this, read the article from Vice titled: “Oklahoma Will Not Execute Another Prisoner This Year.