Dunham says that since the ruling other executions have occurred but Midazolam was not a part of the protocol.

CNN: Justice Breyer on revisiting the death penalty

The lawyers, while unable to argue against Midazolam, are likely to file a flurry of other claims before Wednesday's deadline.

CNN: Justice Breyer on revisiting the death penalty

An inquest at the time was unable to establish how she had come to have Midazolam in her body.

BBC: Nurse 'killed colleague after drugging her'

Midazolam, is used in a handful of states.

CNN: Justice Breyer on revisiting the death penalty

"Although the use of Midazolam in this case has already been decided, the case raises very thorny questions about whether Oklahoma will be executing a potentially innocent man with a potentially tortuous drug, " said Robert Dunham of the Death Penalty Information Center.

CNN: Justice Breyer on revisiting the death penalty

Detective Orlando Martinez of the Los Angeles Police Department detailed what Murray told detectives he gave Jackson on the final day of his life, which included the sedative Valium (diazepam), the anti-anxiety drug Ativan (lorazepam), the sedative Versed (midazolam), and 25 mg of propofol.

CNN: Drugs that killed Jackson for clinical use only, experts say