Purkey confessed to the crime while serving a life sentence for the murder of 80-year-old Mary Ruth Bales, whom he beat to death with a claw hammer in October 1998.

In 1992, counselors evaluated Purkey and found he was a classic psychopath; however, his education and intelligence seemed to moderate his antisocial tendencies.

The following year, Purkey's family and friends sent letters to the Kansas Parole Board asking for his release, arguing he had matured and was ready for freedom.

Following the interview, Purkey smoked crack cocaine and prowled the streets in his white Ford pickup truck.

Not wanting to go with him, Long asked to be let out of the vehicle, causing Purkey to retrieve a boning knife from the glove compartment, which he threatened her with.

[6][7] After murdering Long, Purkey stuffed her body into a toolbox and then went to a local bar where he spent hours drinking alcohol.

After burning everything, he took the leftover remains and ashes from the fireplace and dumped them in a septic pond in Clearwater, Kansas.

[5] On October 26, 1998, Purkey, who was now working as a plumber, was called to the home of 80-year-old Mary Ruth Bales, a widow with polio.

[7] Her cause of death was later determined to be blunt force trauma resulting from several strikes to her skull.

After beating Bales to death, Purkey and the prostitute remained at the house for several hours, where they smoked more crack cocaine and ate food in the fridge.

[9] The company which Purkey worked for, Reddi Root'r, later agreed to pay Bales's family $500,000 to settle a negligence lawsuit over their failure to perform a background check on him.

The two officers told Purkey they would give whatever information he revealed to the U.S. Attorney General, but could not make any other promises.

[11] Over the next few days, Purkey gave a handwritten and oral confession and led Tarpley and Howard to the crime scene and the septic pond where he disposed of Long's remains.

[11] In March 2000, Purkey pleaded guilty to felony first degree murder and aggravated robbery for killing Bales in Wyandotte County District Court.

[12][13] On October 10, 2001, federal prosecutors charged Purkey with kidnapping a child resulting in death for Long's murder.

He claimed she was a sex worker who voluntarily traveled with him to Kansas and that he lied about the kidnapping aspect of the murder to ensure a federal prosecution.

[17] During his sentencing hearing, the government produced several witnesses who attested to Purkey's lengthy history of violence.

[20] He was transferred to the United States Penitentiary in Terre Haute, Indiana and was placed on federal death row.

[22][23] On November 20, 2019, U.S. District Judge Tanya Chutkan issued a preliminary injunction preventing the resumption of federal executions.

Purkey and the other three plaintiffs in the case argued that the use of pentobarbital might violate the Federal Death Penalty Act of 1994.

Dr. Gail Van Norman, who reviewed the autopsy, stated Purkey experienced "flash pulmonary edema," a condition that can only occur when a person is still alive.

According to Van Norman, the results affirmed the opinion that premortem flash pulmonary edema is a virtual medical certainty in any execution carried out by the federal government of the United States using pentobarbital.

[32] DeJong's autopsy showed evidence that fluid had built up in Purkey's lungs and spilled into his airways up to his trachea, which would cause a near-drowning sensation during the execution.

The autopsy results also showed that Purkey's lungs had increased in weight due to the fluid build-up.