With the U.S. Supreme Court's ruling that midazolam can be used in lethal injections, here's a look at the states where the sedative has been implicated in several flawed executions or where it is or has been listed in prison system protocols:
STATES THAT HAVE USED MIDAZOLAM:
Executions are on hold amid a lawsuit seeking information about the drugs to be used. Once executions resume, the state will attempt to use pentobarbital or sodium pentothal as a sedative in its two-drug protocol - and use midazolam only if the other drugs cannot be found.
Joseph Rudolph Wood gasped and snorted for more than 90 minutes during his July 23 execution, during which the state used 15 doses of a midazolam-painkiller mix. He was pronounced dead nearly two hours after his execution started.
Arizona will not say whether it has any doses of midazolam left. It is among states that have struggled to find a reliable source for execution drugs since 2010 because of requirements that they identify their supplier.
It has conducted 11 executions that included the use of midazolam.
Attorney General Pam Bondi asked the state Supreme Court on Monday to lift a stay of execution for Jerry Correll, who won a temporary reprieve while the U.S. Supreme Court reviewed the midazolam case brought by lawyers for Oklahoma inmates.
Florida justices previously reviewed midazolam and upheld its use.
Florida inmate William Happ appeared to remain conscious longer on Oct. 15, 2013, than inmates executed under other protocols, according to the lawyers in the Oklahoma case.
Florida officials have not said whether they have an ongoing source of midazolam after conducting three executions in the past year.
It eliminated midazolam from its execution protocol following the prolonged execution of Dennis McGuire on Jan. 16, 2014. He gasped during the 26 minutes it took him to die.
Ohio now intends to use two other drugs, neither of which it has in its possession.
The state has conducted two executions with midazolam as part of a three-drug protocol.
On April 29, 2014, Clayton Lockett writhed and groaned during an execution that included midazolam. The prisons director halted the execution but Lockett died 43 minutes after his execution started; investigators said an intravenous line was placed poorly.
In another execution that included the use of midazolam on Jan. 15, Charles Warner said "My body is on fire" but showed no obvious signs of distress.
After the court's ruling Monday, Oklahoma's attorney general notified the state's Court of Criminal Appeals that the three inmates who challenged the use of midazolam have exhausted their appeals. The prison system said Monday it has enough drugs to put them to death, but wouldn't say whether it had a reliable continuing source.
STATES THAT HAVE AUTHORIZED BUT NOT USED MIDAZOLAM:
Midazolam was approved as the first drug in a three-drug protocol after it ran out of other drugs.
The state's attorney general said after last year's flawed executions that there was no proof inmates had suffered because of the drug.
The state agreed to place executions on hold pending the decision of the U.S. Supreme Court, and wrote a "friend of the court" brief joined by 12 other states asking the court to OK the use of midazolam.
Alabama officials won't say whether they have midazolam, or a reliable source for it.
Legislators approved the use of midazolam this year but the state Department of Correction is still developing a new protocol.
Arkansas has 33 death row inmates. Executions aren't being set while there is a challenge over whether the state can keep confidential the source of its lethal injection drugs.
The state does not have a midazolam supply. Gov. Asa Hutchinson directed prison officials Monday to begin looking.
Arkansas was among states to join Alabama's court brief.
Midazolam is approved as part of a two-drug protocol, with hydromorphone - the same combination used in the troubled executions in Arizona and Ohio last year.
State lawyers last week asked that a trial in a lawsuit challenging the constitutionality of the state's procedures be delayed due to the protocol's "fluid state."
A lawyer for the state says Louisiana doesn't have any lethal injection drugs on hand at the moment, though the state doesn't have any executions pending. The state will not say who will supply execution drugs - one of the issues in the current lawsuit.
Louisiana, too, joined Alabama's "friend of the court" brief.
Midazolam was approved in 2014 as the first in a three-drug protocol that includes a paralytic agent and a drug that stops the heart, but it hasn't been used in an execution yet.
The state's supply expires at the end of September, but no executions are scheduled before then. The state isn't sure whether it will be able to acquire additional midazolam to replace the current batch.
State protocols allow two other medications as a sedative, but Department of Corrections spokeswoman Lisa Kinney said Virginia doesn't have those drugs and can't obtain them.
Colorado and Wyoming also joined Alabama's court filing but don't specifically mention midazolam in their protocols.
Colorado calls for the use of sodium pentothol and two other drugs.
Wyoming, which has no one on death row, specifies the use of intravenous drugs but doesn't direct prison officials toward specific ones.