( CNN ) -- On Wednesday , July 23 , the State of Arizona executed Joseph Rudolph Wood in the fourth visibly bungled execution this year . The execution began at 1:52 p.m . According to eyewitness Michael Kiefer , `` Wood was unconscious by 1:57 p.m. At about 2:05 , he started gasping . '' He continued to gasp for over 90 minutes . Afterward , eyewitness Troy Hayden reported , `` Joe Wood is dead , but it took him two hours to die . To watch a man lay there for an hour and 40 minutes gulping air , I can liken it to , if you catch a fish and throw it on the shore , the way the fish opens and closes its mouth . '' Kiefer counted more than 640 gasps . Arizona engaged in a failed experiment . Its new execution protocol called for administration of two drugs , midazolam and hydromorphone . The only other time this drug combination had been used was the prolonged and similarly disturbing Ohio execution of Dennis McGuire , who took 24 minutes to die and struggled for air for 10 to 13 minutes . Eyewitness Alan Johnson reported that McGuire `` gasped deeply . It was kind of a rattling , guttural sound . There was kind of a snorting through his nose . A couple of times , he definitely appeared to be choking . '' Faced with these well-documented problems , Arizona adopted Ohio 's procedure but increased the amount of each drug ( from 10 milligrams to 50 milligrams for midazolam and from 40mg to 50mg for hydromorphone ) . The state refused to reveal , however , its process for selecting the new doses or whether it conducted due diligence to determine that its protocol would be more effective . Notwithstanding the changes Arizona made to the drug formula , Wood 's execution went even worse than McGuire 's . Despite requests from Wood 's lawyers , Arizona also refused to reveal the source of its drugs -- including the manufacturer , lot number and expiration date -- and the qualifications of its execution team members . Nothing about this information would compromise the identity of those participating in executions , but it would allow the courts and the public to analyze whether the execution procedures will work as intended and bring about death in a way that meets the requirements of the Eighth Amendment . Callan : Are death penalty delays 'cruel and unusual ' ? Four men -- Michael Wilson , McGuire , Clayton Lockett and Wood -- have been subjected to bungled executions this year . Although the drugs , doses and other details of the procedures differed in each execution , the commonality between them is that the departments of corrections used experimental drug combinations and shielded crucial aspects of their practices in secrecy . Even in the aftermath of the executions , the lack of transparency continues . While governors in both Oklahoma and Arizona have called for reviews of the problematic executions , no outside authorities have been brought in to conduct the investigations . Internal investigations are insufficient to the task . Departments of corrections can not be allowed to provide pat explanations that leave central questions unanswered , minimize errors and hide relevant information about what went wrong . Instead , there must be independent investigations of each execution that goes awry and thorough , public reporting of the results . Without truly independent investigations , it will be impossible to make meaningful conclusions about what went wrong or to determine if changes can be made to ensure that the same errors do not happen again . Chemical mix and human error lead to controversial executions . The botched executions in Arizona , Ohio and Oklahoma show us that when states are allowed to devise novel , untested execution protocols without judicial scrutiny or public oversight , the resulting procedures are unreliable . And when the unreliable procedures are implemented , the consequences are gruesome and horrific . States can not be allowed to continue carrying out death sentences without judicial review of their execution procedures . The courts must require departments of corrections to disclose key aspects of these procedures , particularly with respect to the provenance of the drugs used and the qualifications of the execution personnel . Without this oversight , botched executions will become the new norm . No additional executions should proceed until the states act with transparency , and the courts scrutinize execution procedures to ensure that they comport with the U.S. Constitution . Join us on Facebook.com/CNNOpinion .
Four men have been subjected to botched executions this year , authors say . In Arizona , it took Joseph Wood two hours to die . Authors say states veil their procedures in secrecy , contributing to the problem . Score: 6