Kelley Ends His Life as Göring Did
Kelley had returned to a busy civilian life, at various times practicing psychiatry, running a psychiatric hospital, teaching, lecturing and working on his book, 22 Cells in Nuremberg, published in 1947. His public statements often focused on his experiences at Nuremberg and his conclusion that Nazis weren’t all that different from other people.
“Without Hitler, these people are not abnormal, not pervert[ed], not geniuses,” he told the Nashville Tennessean. “They are like any aggressive, smart, ambitious, ruthless businessman.”
Not everyone agreed with Kelley’s diagnosis. Gustave Gilbert, a psychologist who briefly served alongside him at Nuremberg, took a different view. Gilbert had stayed through the trials and written a popular book about them, Nuremberg Diary.
Unlike Kelley, Gilbert maintained that Nazis were indeed a breed apart. Göring, he concluded, was an “aggressive psychopath.” Both Kelley and Gilbert have since been faulted for trying to explain the “Nazi mind” from such a small sample size.
Kelley transitioned from psychiatry into criminology, becoming a go-to consultant for police departments in California, where his family was now living, and a star witness in headline-making criminal cases. When the director Nicholas Ray wanted an expert on juvenile delinquency to review the script for his 1955 film Rebel Without a Cause, he chose Kelley for the job. Kelley also began appearing on a local TV program called “Science in Action.”
From all appearances, Kelley had found professional success. But his home life in Berkeley was another story. He drank heavily, fought with his wife and behaved tyrannically toward his son, says El-Hai. 
On New Year’s Day 1958, apparently after a fight with his wife, Kelley stormed off to his upstairs study, then emerged to announce that he was about to take cyanide and would be dead in 30 seconds. After putting something in his mouth and swallowing, El-Hai writes, he collapsed “like a slackened marionette.” Witnessing the event were Kelley’s wife, father and 10-year-old son. Kelley was dead on arrival at a Berkeley hospital.
'He Must Have Just Cracked'
The irony of Kelley dying the same way as his most famous patient was lost on no one. Some early accounts even suggested he might have snuck the poison home from Nuremberg, although evidence soon emerged that it came from a U.S.-based chemical supply house.
Friends and associates struggled to understand his decision, with many newspaper headlines deeming it a mystery. “He must have just cracked—boom, like that,” Berkeley’s police chief, a close friend of Kelley’s, told a reporter. Others blamed overwork or a stomach ailment.
At least one newspaper noted another irony: His January 6 episode of “Science in Action” was supposed to have been devoted to “the science of happiness.”
Whatever Kelley’s motivation, El-Hai writes, “the cyanide was a deliberate evocation of Göring’s defiant suicide…. It is no coincidence that cyanide, a poisonous agent with a uniquely dramatic effect on the body, was their selected means of escape.”
The two men—very different in many ways, surprisingly similar in others—would now be forever entwined in history. 
If you or someone you know is struggling with suicidal thoughts or self-harming behaviors, call or text 988 to get help from the 988 Suicide & Crisis Lifeline.