Charles Manson is finally dead. There is no resting in peace for such a person. At his trial, Manson told the prosecutor Vincent Bugliosi that he was already dead. He had said previously that he had been dead for 2,000 years, part of the confused allusions he made to being Christ. The terrible murders he committed in 1969 and his courtroom testimony transfixed America. The cult leader was finally starring in his own movie, strutting and fretting his hour upon the stage – a short, long-haired man full of violence, rage and manipulation.

Now, if you care to look on the internet, Manson’s ramblings are memorialised on various websites, like inspirational quotes complete with images. The court could not break him, but then he had been broken and killed many times over many years ago, he claimed. There was some truth in it, although not the whole truth. Never that. These quotes may not be inspirational but they remain influential: the killer as the apotheosis of alienation, a strange object of admiration.

Now that Manson really is dead, will his influence – if he really was anything other than a con man and a paranoid schizophrenic – live on in our culture? His name itself is a shortcut to some edgy, wicked outsider mentality: Marilyn Manson; Kasabian (named after Linda Kasabian, a member of Manson’s cult).

Quick Guide A quick guide to Charles Manson Show Who was Charles Manson? Charles Manson was one of the most notorious murderers of the 20th century. He led a cult known as the Manson Family in California, most of whom were disaffected young women. Some became killers under his messianic influence. Murder from afar Despite spending more than 40 years in prison for the murders of seven people in 1969, Manson did not carry out the killings. Instead he convinced members of his ‘family’ to murder. One of their victims was the actor Sharon Tate, who was married to Roman Polanski and was more than eight months' pregnant when she was killed. Celebrity friends By the time of his trial in 1971, Manson had spent half of his life in correctional institutions for various crimes. He became a singer-songwriter before the Tate murders and got a break in the music industry when he met Beach Boys' Dennis Wilson, who let him crash at his home. Helter Skelter It is believed that Manson intended using the murders to incite an apocalyptic race war he called Helter Skelter, taking the name from the Beatles song. Notorious by name The killings and the seven-month trial that followed were the subjects of fevered news coverage in the US. Manson occupied a dark, persistent place in American culture, inspiring music, T-shirts and half the stage name of musician Marilyn Manson. Photograph: Los Angeles Times

In interviews conducted in his later years in prison, where he says spiders he fashioned out of the yarn of his socks allowed him to control the world, Manson comes across as old, pathetic, bewildered, mentally ill. These are what people should take a look at. Yet at the time of the murders – the details of which are still so absolutely shocking (the X cut on murdered Sharon Tate’s pregnant belly) – society was still strangely ambivalent about him.

Manson appeared on the cover of Rolling Stone, a Christ-like image with a headline asking if he was the most dangerous man in America. Rock star murderer? The myths abounded: he had an audition for the Monkees (this is doubtful); he communicated to his followers from prison telepathically, as they all carved swastikas on their foreheads the same day. Then there is the ongoing argument that he didn’t actually murder anyone himself, he just got them to do it instead.

The reality was both more prosaic and ugly. He had been in and out of prison all his life, where he learned to be abused and how to abuse – he actually asked to stay in prison knowing he was unfit for life outside it but the plea went unheeded and he became a pimp and a thief offering suburban girls drugs and his psychopathic version of family. Having been rejected by mainstream society he was also rejected by the counterculture, and could not make his way in the music scene.

His anger and sense of omnipotence gave him a kind of charisma. His overriding fantasy was of a race war. He was a loser who would become a winner, and he would do it through white supremacy. The thing he called Helter-Skelter would ignite this war. This was the rationale for the slayings. It was a holy war then against the rich and the powerful. The racial aspects seem to me to be forgotten by those who sought to understand him and who gave him the attention he craved. Dennis Hopper went to see him in prison, and film director John Waters attended the trial.

The Manson murders were seen to represent the end of the counterculture – peace and love giving way to brutal murder. But parts of the culture turned Manson into a strange kind of idol.

The racial aspects seem to be forgotten by those who sought to understand him and who gave him the attention he craved

Joan Didion, in her 1979 essay The White Album, recounts hearing of the murders at Roman Polanksi’s house on Cielo Drive. The numbers of dead were not yet finalised but there was talk of black masses and bad trips, hoods and chains. She said: “And I also remember this and wish I did not: I remember that no one was surprised … At a stroke, the 60s ended – the paranoia was fulfilled.” Celebrity and fame were no protection against the darkness, and Didion describes the unease everywhere. She recalls too how she helped Kasabian, who testified against Manson’s group, find a short green velvet dress to wear for the trial.

This is a long, long time ago, but the mythology around Manson and his cult never quite goes away. His songs, such as they are, have been recorded by Guns N’ Roses, Marilyn Manson, of course, and GG Allin, among others. What truths do they tell? He has been interviewed in prison, and movies have been made about him. Most killers do not get this sort of treatment, let alone purveyors of white supremacism.

His death comes though as his pernicious beliefs in a race war have entered the American mainstream. His warped logic holds sway at the highest levels of US society. Was he evil or mentally ill? Or was he in fact a product of a system that has not changed in all these years. When he said in court: “My father is the jailhouse. My father is your system … I am only what you made me. I am only a reflection of you,” he told America something. And it was awful. He died an old pathetic and disturbed man. A banal monster. Nothing special. Remember that – and his victims.

• Suzanne Moore is a Guardian columnist