Last Updated Sep 4, 2014 12:45 PM EDT
OKLAHOMA CITY -- The intravenous line inserted into the groin of an Oklahoma inmate who writhed and groaned before dying 43 minutes after his execution began was not properly monitored, according to a state review released Thursday, which also recommended more training for prison officials and medical personnel.
The review, released by the Oklahoma Department of Public Safety, cited problems with Lockett's IV line, which caused swelling the size of a golf ball.
"This investigation concluded the viability of the IV access point was the single greatest factor that contributed to the difficulty in administering the execution drugs," according to the DPS report. The agency's commissioner was appointed by Fallin.
Fallin had no immediate comment on the report, nor did a corrections department spokesman.
Department of Public Safety Commissioner Michael Thompson said that, "at the end of the day ... the drugs did what they were designed to do."
Oklahoma used the sedative midazolam for the first time in Lockett's execution. That drug was also used in lengthy attempts to execute an Ohio inmate in January and an Arizona prisoner last month. Each time, witnesses said the inmates appeared to gasp after their executions began and continued to labor for air before being pronounced dead.
But Oklahoma's review didn't find fault with midazolam or other drugs, instead noting that the IV troubles made it difficult to determine the drugs' effectiveness.
A paramedic and physician inserted the intravenous line in Lockett's groin after failing to find suitable veins in his arms, legs, neck and feet. The report says the IV site was covered with a sheet and not monitored until Lockett began moving unexpectedly after receiving two doses of drugs.
"The physician observed an area of swelling underneath the skin and described it as smaller than a tennis ball, but larger than a golf ball. The physician believed the swelling would have been noticeable if the access point had been viewed during the process," the report said.
State prisons director Robert Patton halted Lockett's execution, and Lockett died behind a shuttered curtain 43 minutes after his execution began.
Patton said the cause was a heart attack, but autopsy results released last week said he died from the drugs: midazolam, vercuronium bromide and potassium chloride. The autopsy did not explain why the execution took so long or why Lockett writhed.
Prison officials previously said Lockett was combative in his cell on the morning of his execution and that he may have intentionally dehydrated himself to make it more difficult for the IV to be placed. But the report said Lockett had no signs of dehydration at the time of his death and that self-inflicted cuts on his arms shouldn't have affected IV access. The report also noted medical personnel examined said Lockett's veins were good or acceptable for IV access.
Lockett's execution was to be the first of two executions held back-to-back on April 29, but the second execution was postponed that night.
The DPS report recommended that the state hold executions at least seven days apart, noting that the prison warden believed that the planned double execution caused "extra stress" for staff members.
Lockett, 38, had been convicted of shooting Stephanie Nieman, 19, with a sawed-off shotgun and watching as two accomplices buried her alive in 1999.
Three executions have been set in Oklahoma for November and December. One of the inmates is Charles Warner, who was supposed to die the same day as Lockett.