It's not the kind of book I normally read. Urged by a friend many years ago to read Ed Sanders's The Family—he lent me his copy— I did so, and that was more than enough Manson for me.

The subtitle is of a sort that made me feel presumptively fatigued. I'm not interested in going down rabbit holes.

And yet, a brief recommendation of Chaos by a TLS contributor who selected it as his Book of the Year made me curious enough to pick it up. And once I started reading it I didn't want to put it down.

Some of the disappointment voiced by the book's detractors seems to stem from the fact that Chaos raises questions that it cannot answer.

But the existence of these questions themselves, often based on real evidence of crimes committed by our society's law enforcement officers, should be enough for investigation at the highest possible levels.

These same questions also involve CIA mind-control experiments and the dreaded JFK assassination and investigation. O'Neill is very aware that he puts his credibility on the line as he pursues the lines of inquiry that lead him into these areas.

And that's the real story of Chaos. This is not a book about Charles Manson, who plays a relatively small part here, managing to be somehow central and peripheral at the same time.

The real subject is an investigation and an investigator: a journalist who asks some questions that lead him to more questions that lead him to more questions. By the time he's gathered everything into a book, he's spent twenty years following a trail that involves threats, lawsuits, huge amounts of debt and immeasurable sacrifice and ends in the demolition of most of what we always thought we knew about the Manson Family.

O'Neill can't replace the old picture with a new one. If it had been possible, I believe that he would have done it.

His sources are often the FBI and CIA's own files as well as agents' testimony at congressional investigations. In other words, the least impeachable evidence you could ask for.

It was a horrible time. You could violate the Geneva Conventions in Vietnam, then go home, transfer from the military to law enforcement and violate due process. After that you get into politics and you stay there for the next several decades doing God knows what.

Consider one of the threads O'Neill follows, one of the shorter and less tangled ones.

O'Neill suspects CIA involvement but the agency responds to his Freedom of Information Act request by refusing to confirm or deny any connection with Herrmann.

Herrmann also spent time in Vietnam and O'Neill notes that everything about him and the dates he was there "made it abundantly likely that he was working for a CIA project called Pheonix".

What was Phoenix? In the CIA's own words, it was "a set of programs that sought to attack and destroy the political infrastructure of the Viet Cong".

When Herrmann comes back from Vietnam, he quits his job with the Los Angeles Police Department and accepts Governor Ronald Reagan's offer to take charge of a newly created Riots and Disorders Task Force. At the same time the FBI's COINTELPRO program and the CIA's CHAOS program were attempting to attack dissidents and activists from the inside, as well as conduct illegal surveillance on thousands of American citizens.

What does any of this have to do with Manson? This and many other operations and people like Herrmann, are shown in this book to be extremely close to Manson, and Manson himself bafflingly immune from arrest or punishment for parole violations. Almost as if powerful people wanted him left alone.

It probably sounds crazy. But there's no easy way of just saying it or even suggesting it. That's why O'Neill spent two decades slogging through thousands of documents and thousands of hours of interviews and countless hours of work and travel and frustration and, well, chaos.

The first line is: "Vincent Bugliosi was on another tirade".