The once mild-mannered young Los Angeles prosecutor whose dogged investigation put mass-murderer Charles Manson and several members of his “family” behind bars, died Saturday of cancer in Los Angeles, his son confirmed. He was 80.

Although Bugliosi conceded that the Manson trial would forever define his career (the case provides the backdrop for David Duchovny’s new NBC series Aquarius), he went on to become a celebrated prosecutor with a near-perfect record of convictions and a bestselling crime writer who took on such explosive subjects as the assassination of JFK (the 1,600-page Reclaiming History: The Assassination Of President John F. Kennedy) and the unsuccessful prosecution of O.J. Simpson (Outrage: The Five Reasons Why O. J. Simpson Got Away With Murder).

Vincent BugliosiIn 2008, Bugliosi wrote The Prosecution Of George W. Bush For Murder, a blistering polemic calling for the indictment of the President for what he called the murder of 4,000 American servicemen and 100,000 Iraqi civilians following the 2003 invasion of that country under, what he argued, were false premises and illegal circumstances. A documentary of the same name drew a mixed New York Times review, with critic Andy Webster writing that “there is no mistaking Mr. Bugliosi’s conviction, nor the thoroughness of his research, which largely concerns the Bush administration’s claims of Iraqi weapons of mass destruction. Theories about Mr. Bush’s motives are presented, but, Mr. Bugliosi says, prosecutors are not burdened with proving a motive.

“Emotional support comes in grisly news footage: civilians being shot; gravely wounded troops; a father’s self-immolation after learning his son, a Marine, is dead. These images remind us of how American lives are used as political chess pieces, and how agonizing it is when the game’s larger objective remains unclear.”

Still, it was the 1971 Manson trial and, three years later Helter Skelter, Bugliosi’s harrowing bestselling account of it, that remain first in the public knowledge of him. The murders took place just a week before the Woodstock festival of “peace, love & music” unfolded on a rain-soaked farm in upstate New York. But like the Altamont Festival held four months later, the Manson murders came to be identified with the bitter end of the Age of Aquarius.

Charles Manson, 1970“If I were to give you what I believe to be the single most important reason,” Bugliosi told National Public Radio in 2009 about global interest in the brutal murders of Sharon Tate and six others, it “is that the murders were probably the most bizarre in the recorded annals of American crime. I mean, the incredible motive for the murders: to ignite a war between blacks and whites, that Manson called helter skelter, would be the last final destructive on the face of this Earth, according to him.

“Who were the killers?” he asked rhetorically. “Young kids from average homes of fairly good backgrounds, completely different from what we would expect of mass murderers. The very thought of young women dressed in black, armed with sharp knives entering the homes of total strangers in the middle of the night, is really so horrendous a thought that it’s difficult to contemplate a thought like that.”