Beacon Journal wire services

McALESTER, Okla.: Oklahoma called off a high-profile double execution with an experimental drug combination Tuesday evening after the first execution was apparently botched and the inmate died of a heart attack about 40 minutes after the drugs were administered, according to news reports.

Clayton Lockett was slated to be the first to die after a legal battle over Oklahoma’s lethal-injection methods, which have come under fire from death penalty opponents for the secrecy surrounding the process.

Director Robert Patton said Lockett died Tuesday after all three drugs were administered. Patton halted Lockett’s execution about 20 minutes after the first drug was administered. He said there had been vein failure.

The execution began at 6:23 p.m. when officials began administering the first drug, and a doctor declared Lockett to be unconscious at 6:33 p.m.

About three minutes later, though, Lockett began breathing heavily, writhing on the gurney, clenching his teeth and straining to lift his head off the pillow. After about three minutes, a doctor lifted the sheet that was covering Lockett to examine the injection site.

“There was some concern at that time that the drugs were not having that [desired] effect, and the doctor observed the line at that time and determined the line had blown,” Patton said at a news conference afterward, referring to Lockett’s vein rupturing.

Patton made a series of phone calls before calling a halt to the execution.

He also issued a 14-day postponement in the execution of inmate Charles Warner, who had been scheduled to die on Tuesday, two hours after Lockett was put to death.