OKLAHOMA CITY — The team responsible for executing an Oklahoma inmate failed multiple times to insert an intravenous line into his body to deliver lethal drugs, even though the man’s veins were in good condition, according to a private autopsy released Friday by attorneys for Oklahoma death row prisoners.

After the botched execution of Clayton Lockett, prison officials had said an IV specialist was unable to find suitable veins on his arms, legs or feet. Oklahoma executions typically involve IVs inserted into both arms. A doctor overseeing the April 29 execution suggested tapping a vein in Lockett’s groin area, and said Lockett did not receive a full dose of the three lethal drugs after his vein collapsed.

But forensic pathologist Dr. Joseph Cohen said his preliminary findings indicate that Lockett had healthy veins, and it appears the execution team tried repeatedly to insert an intravenous line without success, including into deep veins on both sides of Lockett’s groin.

Cohen cited the “excellent integrity of peripheral and deep veins for the purpose of achieving venous access.” He also said Lockett’s body had numerous puncture wounds from multiple attempts to tap them and he found signs of “failed vascular catheter access.”

He said more information was needed to determine why Lockett died. Prison officials have said he died of an apparent heart attack. Results from the initial state autopsy are still pending, however, and toxicology reports haven’t been released – so it’s unclear how much of the drugs Lockett received.

Prison officials have not said who inserted the IV, and state law allows the identities of the doctor and the IV expert to remain secret. Oklahoma prisons spokesman Jerry Massie said Friday the IV specialist was a certified emergency medical technician, but declined further comment until an investigation into the botched execution is completed by the Oklahoma Department of Public Safety.