A condemned Arizona inmate gasped for more than an hour and a half during his execution Wednesday before he died in an episode sure to add to the scrutiny surrounding the death penalty in the U.S.

Arizona Attorney General Tom Horne's office said Joseph Rudolph Wood was pronounced dead at 3:49 p.m., one hour and 57 minutes after the execution started.

Wood's lawyers had filed emergency appeals with federal and state courts while the execution was underway, demanding that it be stopped. The appeal said Wood was "gasping and snorting for more than an hour."

Gov. Jan Brewer said later that she's ordering a full review of the state's execution process, saying she's concerned by how long it took for the administered drug protocol to kill Wood.

An Associated Press reporter who witnessed the execution saw Wood start gasping shortly after a sedative and a pain killer were injected into his veins. He gasped more than 600 times over the next hour and 40 minutes.

An administrator checked on Wood a half dozen times. His breathing slowed as a deacon said a prayer while holding a rosary. The 55-year-old finally stopped breathing and was pronounced dead 12 minutes later.

"Throughout this execution, I conferred and collaborated with our IV team members and was assured unequivocally that the inmate was comatose and never in pain or distress," said state Department of Corrections Director Charles Ryan.

Read more at the Associated Press

See the video below from AZ Central