Oklahoma is planning to become the first US state to use nitrogen gas for executions, state officials said Wednesday while announcing the resumption of carrying out the death penalty after a three-year hiatus, according to dpa. The new method was announced in a statement from Attorney General Mike Hunter and Department of Corrections director Joe Allbaugh. The gas method was chosen as it was "effective, simple to administer, easy to obtain and requires no complex medical procedures," Hunter said. "I believe in justice for victims and their families, and in capital punishment as appropriate for dealing with those whose commit these crimes," he added. Victims of death row inmates had waited long enough for justice, Allbaugh said. "Trying to find alternative compounds or someone with prescribing authority willing to provide us with the drugs is becoming exceedingly difficult, and we will not attempt to obtain the drugs illegally," he said. Executions in the state were suspended following the botched execution of Clayton Lockett on April 29, 2014. The convicted murderer attempted to leave the gurney, groaned, convulsed and spoke in the 43 minutes after he was sedated for lethal injection. He finally died of a heart attack. The new scheme could take three to four months to be implemented, Hunter said, plus a 150-day federal review waiting period.