A North Carolina federal judge said he will stop an execution scheduled for later this month unless state officials tell him by Wednesday how they will ensure the inmate is unconscious as he's being put to death.

U.S. District Court Judge Malcolm Howard issued the ruling Friday in the case of condemned killer Willie Brown Jr. Brown, 61, was sentenced to death for the 1983 Martin County slaying of Valerie Ann Roberson Dixon. He is scheduled to die April 21.

State prosecutors must confirm by noon Wednesday that appropriate medical personnel will be on hand for Brown's planned execution to make sure that he's unconscious and to immediately put him back to sleep if there's any sign of his awakening. State officials didn't respond immediately to a request for comment.

The case is parallel to a February case in California, where an execution was canceled after doctors refused to participate. A lawsuit on Brown's behalf challenges the state's method of execution by injection, saying inmates may suffer pain if they're not properly sedated. The state procedure is to inject a drug that puts inmates to sleep, then others that paralyze and kill them.

“Serious questions have been raised by the evidence concerning the effect of the current execution protocol,” Howard said in his order. “If the alleged deficiencies do, in fact, result in inadequate anesthesia prior to execution, there is no dispute that Brown will suffer excruciating pain.”

During an execution in March, prison officials wouldn't comment when asked if there were medical personnel present when the drugs were injected.