Richard Eugene Hickock was born in Kansas City, Kansas, to farmworker parents, Walter Sr. and Eunice Hickock. He was a popular student with great intelligence and was an athlete at Olathe High School before head injuries from a serious automobile accident in 1950 left him disfigured, and resulted in his face being slightly lopsided and his eyes asymmetrical. Although he had wanted to attend college, his family lacked the means to provide this, so he went to work as a mechanic. He married, but then became involved in an extramarital affair, eventually leading to the conception of his first child. He then decided to end his marriage to marry his mistress; that marriage also ended in divorce after two more children. He turned to petty crime, such as cheating and using fraudulent checks, to help make ends meet. He eventually landed in prison, where he met Smith and hatched a plan for robbery and murder.

Along with Smith, Hickock was arrested in Las Vegas, Nevada, on December 30, 1959, for the Clutter family murders, for which they were both tried and found guilty. They both talked extensively to Capote when he was researching In Cold Blood.

Hickock and Smith were executed by hanging at the Kansas State Penitentiary on April 14, 1965. When asked if he had any last words, Hickock declined, but he requested to address the KBI agents who had worked on his case and now were present as witnesses to his execution. Hickock told them that he had "no hard feelings" towards them; he shook each agent's hand and simply said, "Goodbye." Smith, in contrast, attempted to speak beyond the room when he addressed the media representatives and declared "capital punishment is legally and morally wrong." Hickock was executed first and was pronounced dead at 12:41 am; Smith followed shortly after and was pronounced dead at 1:19 am.

Hickock was portrayed by Scott Wilson in the 1967 film adaptation of In Cold Blood; by Anthony Edwards in the 1996 TV miniseries adaptation; by Mark Pellegrino in the 2005 film Capote; and by Lee Pace in the 2006 film Infamous.

The bodies of the killers were exhumed December 18, 2012, from Mount Muncie Cemetery, as authorities hoped to solve a 53-year-old cold case using DNA. The two were questioned about the December 19, 1959 shooting murder in Osprey, Florida, of Cliff and Christine Walker and their two young children. Smith and Hickock had fled to Florida after the Clutter murders. A polygraph administered at the time of their arrest in the Clutter case cleared them of the murder, but by modern polygraph standards, their test results are no longer considered valid. On December 19, 2012, officials in Kansas exhumed the bodies of Smith and Hickock and retrieved bone fragments in order to attempt to compare their DNA to semen found in the pants of Christine Walker. In August 2013, the Sarasota County Sheriff's office announced they were unable to find a match between the DNA of Perry Smith or Richard Hickock with the samples in the Walker family murder. Only partial DNA could be retrieved, possibly due to degradations of the DNA samples over the decades or contamination in storage, making the outcome one of uncertainty (neither proving nor disproving the involvement of Smith and Hickock). Consequently, investigators have stated that Smith and Hickock still remain the most viable suspects.