The state of Arizona killed Joseph Wood by lethal injection Wednesday in an execution process that took almost two hours. The botched lethal injection was just one of several that have been carried out in the United States in the past few months.

The execution took place around 1.30 p.m. local-time. After Wood’s arms were injected with two lines, his veins were filled with a combination of the drugs midazolam and hydromorphone. According to an eyewitness with the Associated Press (AP), a look of pain overtook Wood’s face, and then he closed his eyes.

Ten minutes into the execution, roughly the amount of time lethal injections usually take to kill someone, Wood began gasping. Eyewitnesses reported that his jaw suddenly dropped and his chest puffed up. Afterwards he let out a gasp. AP reported: “The gasps repeated every five to 12 seconds. They went on and on, hundreds of times.”

After some time, the executioner turned on the microphone to the observers and informed them that Wood was, in fact, sedated, despite the noises he was making.

Troy Hayden, an eye witness to the execution, told USA Today that the execution was “very disturbing to watch … like a fish on shore gulping for air.” A reporter for the Arizona Republic, Michael Kiefer, said he “counted about 660 times he [Wood] gasped.”

As the execution continued, with the repeated gasping ongoing, Wood’s lawyers drew up an emergency appeal to the Arizona Supreme Court asking that the execution be immediately stayed.

In their plea they wrote, “He has been gasping and snorting for more than an hour… He is still alive.” Indicting the state, they concluded: “This execution has violated Mr. Wood’s Eighth Amendment right to be executed in the absence of cruel and unusual punishment.”

The legal team drew attention to Arizona State law’s “Contingency Procedure” for executions, which states: “If at any point any team member determines that any part of the execution process is not going according to procedure, they shall advise the IV Team Leader who shall immediately notify the Director. The Director may consult with persons deemed appropriate and will determine to go forward with the procedure, start the procedure over at a later time within the 24-hour day, or stand down.”

The Supreme Court of Arizona held an emergency session by telephone in response to the lawyer’s motion; however, Wood was pronounced dead an hour later, while the court was still discussing the issue.

In April of this year, the state of Oklahoma killed Clayton Lockett in a 43-minute execution process. After being injected with the lethal drugs, Lockett began kicking and grimacing, trying to lift his head off the gurney to which he was strapped. Lockett’s veins exploded during the execution and he eventually died from a massive heart attack.

State execution chambers have been experimenting with drug cocktails after several European nations banned the export of drugs used for capital punishment to the United States. These experiments have led to multiple executions this year in which the condemned was clearly in profound pain or the killings took multiple times the usual length of ten minutes.

Before Wood was executed, his lawyers demanded that the court provide details regarding the two drugs they were going to use to kill him. His lawyers petitioned the court to stay the execution, which they did temporarily. The lawyers argued that Wood’s death would be both cruel and unusual.

After the execution Wednesday, the American Civil Liberties Union of Arizona denounced Wood’s death and called for a halt to future executions in the state. Alessandra Soler, the Arizona ACLU’s executive director, stated: “What happened today to Mr. Wood was an experiment that the state did its best to hide.” She said that government officials “cannot be trusted to take seriously our Constitution’s ban on cruel and unusual punishment.”

Wood was the 26th person to be executed this year in the United States. He was on death row for a double murder he committed in the late 1980s.