Wang Yiyu was a strong, quick-tempered 16-year-old boy when he killed a 19-year-old Red Guard from a rival faction.
Today he is haunted by the same recurring nightmare, Wang told Phoenix TV: "A woman in a white dress with blood stains predicts 'You will lie [on this bed of guilt] for 10, 000 years.'"
The woman in white has pursued Wang for decades: She first popped up when he was on the run for his crime.
After serving his nine-month murder sentence in 1967, Wang penned an 8,000-word confession "Weighed down by the guilt of murder" and published it in fringe history magazine Yanhuang Chunqiu in May 2010.
Wang's self-described metamorphosis "toward an animal" took "less than five minutes" after an older Red Guard convinced him that beating was in fact a form of class struggle, a way for Wang to demonstrate loyalty.
Soon young Wang would feel a surge of teen "exhilaration" beating up a boy he had protected from others only five short minutes before as he became one of the frontline "combat boys" of his group.
"Younger members were more easily provoked," he said.
On August 5, 1967, after seeing his comrade Li Hongxin had been beaten up by a rival Red Guard faction, Wang and his gang wanted revenge.
Filled with bloodlust, Wang and his faction raced into a trap. More and more rivals arrived at the scene in trucks and Wang's group was by now outnumbered about 10 to one.
The danger fed desperation.
When a boy threw red bricks at his head from behind, Wang wheeled around and landed two heavy blows on his assailant with his baseball bat.
Wang's bat was not the sole instrument responsible for the death of Wang Hongyan. A hole in the side of Wang's neck attested to a javelin employed by one of two other comrades.
Seeing his victim lying in a pool of blood, "I started to feel that he was a human being the same as me, not our class enemy."
Wang looked directly at the camera to his right in the Phoenix TV Beijing studio.
"In those mad times, others didn't murder, but I did. I am a murderer," he told an audience of millions, eyelids twitching.
"There must be darkness inside me. There must be evil inside."
Only his false left eye looked calm. That he had lost his eye in an accident was a kind of delayed karmic retribution, Wang believed. He said other Red Guards he knew had died of liver cancer, leukemia or a gas leak.
"Even if the laws let you get away with it, your conscience will get you," he told the half-hour Secret Documentary TV show.
Through humiliating, public confession, Wang hoped he might at last begin to address his many sins of that era.
"Finally I have done something worthwhile," Wang said. "Later on in studies of the Cultural Revolution, I have contributed a true story."
In places like South Africa or Northern Ireland, confession might merely be considered a precursor whereas in China that's the ending - Wang's confession on Chinese mainland television was among the first of its kind and Phoenix Television is a satellite channel broadcasting to a limited, predominantly urban, Chinese mainland audience.
"It was an admirable act," said Shen Xiaoke, "considering he did kill someone."