Sharon Tate's Murderer Charles Manson Is Dead 

Serial Killer Charles Manson, Whose 1969 Murders Horrified the Nation, Dead at 83

Infamous serial killer Charles Manson, whose name became synonymous with evil after his arrest in connection with the 1969 killings of actress Sharon Tate and eight other people, has died. He was 83 and serving nine life sentences in California’s Corcoran State Prison at the time of his death.

“I said a prayer for his soul,” Debra Tate, whose sister Sharon Tate was murdered by Manson, tells PEOPLE of the moment after she received a call from a prison official informing her of Manson’s death Sunday evening.

A career criminal who spent over half his life in prison before masterminding one of the most notorious mass killing sprees of the 20th century, Manson became the leader of a group of young followers he convinced to murder for him and who became known as the Manson “family.”

The savage slayings shocked and terrified the nation and were part of Manson’s efforts to launch a race war — which he named “Helter Skelter” after the Beatles song.

“Some people glorify him as a sort of master outlaw,” Vincent Bugliosi, who successfully prosecuted the cult leader in 1971, told PEOPLE in 2015. “But he really was nothing more than an evil, very sophisticated con man.”

On Aug. 8, 1969 — having already orchestrated the death of Gary Hinman a month earlier — Manson dispatched three of his female followers to the rented Los Angeles home of pregnant Hollywood star Sharon Tate, wife of director Roman Polanski, and ordered them to kill everyone there.

L.A. police officers who arrived at the hilltop home the next morning stumbled upon a scene of unimaginable brutality that unnerved even the most hardened homicide detectives. At the property at 10050 Cielo Drive were five bodies, including that of Tate, 26, who was eight-months pregnant. She had been stabbed 16 times and had an “X” carved into her stomach.

The next night, Manson ordered his followers to kill again: They descended upon the home of Leno and Rosemary LaBianca and murdered the couple. The word “war” was carved into Leno’s stomach and “Helter Skelter” was scrawled on the couple’s refrigerator in blood.

The murders terrified the residents of L.A., who flocked to gun stores to purchase unprecedented numbers of firearms for protection. The sale of burglar alarms skyrocketed.

Two months later, Manson — who at the time referred to himself as “God” — was arrested after he was found hiding in a bathroom cabinet at a ramshackle ranch in Death Valley, California. Between the Tate-LaBianca killings and Manson’s arrest, he and some of his followers killed again, murdering Donald “Shorty” Shea in late August 1969.

The nation quickly became both fascinated and sickened by the case, which grew even stranger and more macabre as details behind the killers slowly began to emerge.

What made Manson’s carnage even more terrifying to the outside world was that many of his recruits, who willingly participated in the slaughter, were young women.

“They were kids,” says Bugliosi, “from fairly average American homes.”

Former homecoming queen Leslie Van Houten, the youngest of the killers who was 19 at the time, later testified to stabbing Rosemary LaBianca over a dozen times as cohort Patricia Kerwinkle held their victim down.

“I took one of the knives, and Patricia had one knife, and we started stabbing and cutting up the lady,” Van Houten said during her 1971 trial.

Adds director Leslie Libman, who created the 2016 TV movie

: “These were normal girls who weren’t mistreated, but who were rejecting society, embracing this guy who took advantage of them — and changed everything.”

Manson (center) being escorted to court by authorities in December 1969

After a nine-month trial, Manson was sentenced to death in 1971 for conspiracy to commit seven murders. The sentence was reduced to life in prison one year later when California abolished the death penalty.

In the decades that followed, the story of the Manson “family” has been retold in countless movies, books, TV shows and songs.

Last year, Beach Boy co-creator Mike Love detailed the shocking friendship between fellow band mate Dennis Wilson and the cult leader, who was an aspiring singer-songwriter in the days leading up to the Tate-LaBianca murders.

, Manson and his followers moved into Wilson’s spacious L.A. home as Dennis tried in vain to land him a recording contract.

In fact, Manson first visited the residence where his “family” members would slaughter Sharon Tate and her friends a year earlier, during a night out listening to music at clubs with producer Terry Melcher – Doris Day’s son – who eventually turned him down for a recording contract.

“Charlie was a really strange, scary dude with a daunting stare,” Love told PEOPLE, insisting that Wilson, who drowned in 1983, was forever “haunted” by his relationship with the psychopathic killer. “Dennis carried that guilt with him for the last 14 years of his life.”

Despite the passage of nearly 50 years since the murders, the terrible fallout from Manson’s senseless carnage has never gone away for the family members of his victims.

“All my life I’ve seen ‘Sharon Tate and four others killed,’ as if he’s insignificant,” says Anthony DiMaria, whose uncle Jay Sebring, a celebrated hairstylist, was among those murdered at the Tate residence.

“So much fascination and attention has been paid to the crimes and killers,” DiMaria told PEOPLE in 2014. “But for our families, the killings are a life sentence.”

Over the years, Tate’s younger sister Debra, 63, has emerged as one of Manson’s — and his followers’  most vocal and tireless opponents.

“The ones that are left behind are victims as much as the actual victims,” Debra told PEOPLE in 2014. “We are here to suffer for years and years to come.”

She watched helplessly as her family was destroyed by Tate’s murder — eventually finding the strength to fight back when his convicted followers began petitioning for their release from prison.

“For my mother, it was absolutely devastating, and she wasn’t capable of getting beyond the pain,” Debra recalls. “She fell into a horrible depression. She shut everything off. The lights were on, but nobody was home. She would have moments of lucidity, but most of the time she was sedated.”

The two women ultimately became well-known advocates for victims’ rights and soon began appearing at every parole hearing for Manson and his “family” members, something Debra insists she will continue doing for as long as she lives.

“They’re not supernatural, they’re not the devil, they’re nothing special, they’re just little creeps,” she says, confessing that although she dreads the court hearings for the way they “make you relive it all,” she finds satisfaction in seeing that “these people stay in prison for the rest of their lives. The people that we lost in this historical event were real, and they had lives and families. They’re sorely missed. They were truly magnificent people.”

During his decades in incarceration, Manson was anything but a model prisoner, racking up many rules violations that ranged from hiding cellphones, LSD and marijuana in his cell, to throwing feces at guards.

For a period in the 1980s, he was allowed to mix with the general prison population, but that was stopped after an altercation with a fellow prisoner, who ended up dousing him in paint thinner and lighting him on fire.

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