Gary Krist’s most recent book is “Empire of Sin.”

The photograph is unforgettable: that attractive, somewhat diffident young woman — the victim, we thought, of a savage political kidnapping — standing in front of the flag of her captors, clearly one of their number now, with a sawed-off M1 carbine in her hands. For parents of the World War II generation, the image must have been terrifying. What more apt symbol could there be of the increasingly sinister tide of radicalism that was turning their children against them in the late 1960s and early ’70s? Because the message being sent by this child of privilege seemed unmistakable: Screw your concern for me, Mom and Dad. I am now your enemy.

The abduction and subsequent radicalization of Patricia Hearst is one of the most bizarre but illuminating episodes of that tumultuous era of protest (now more than four decades in the past), and in “American Heiress” Jeffrey Toobin retells the story with a full-blown narrative treatment that may astonish readers too young to remember it themselves. Toobin’s subtitle is no exaggeration: The “wild saga” that began with Hearst’s kidnapping by the Symbionese Liberation Army (SLA) on Feb. 4, 1974, would strain credibility in anybody’s novel. But somehow, in the context of real-life California in the big bad ’70s, it was just another day in dystopia. This was, as Toobin reminds us, the age of the Zebra and Zodiac murder sprees, and not long before the Jonestown mass suicides. It was a moment when the counterculture seemed to be downshifting from the hopeful idealism of the Woodstock era to the apocalyptic nihilism of the Watergate years.

The SLA was a case in point. Hardly an army, it was actually just a small cadre of young white radicals led by a charismatic but unstable black ex-convict named Donald DeFreeze. What the SLA lacked in coherent ideology it more than made up for in passionate militancy. In its battle against “the fascist insect that preys upon the life of the people,” the group was willing to bomb, rob, carjack, kidnap and even murder, without being overly fussy about the identity of the target. After several SLA members assassinated the African American superintendent of schools in Oakland in 1973 — for reasons that were nebulous at best — even organizations like the Black Panthers and the Weather Underground condemned the SLA as too extreme and undisciplined.

The kidnapping of Hearst, granddaughter of legendary newspaper publisher William Randolph Hearst, began as another hazy act of provocation. The SLA operated under the “foco theory,” based on the notion that even a minor guerrilla action by a tiny vanguard can be the spark that ignites a full-scale rebellion by the masses. Taking a modern-day aristocrat hostage seemed roughly in line with this philosophy. But Patricia Hearst turned out to be anything but a convenient symbol of the oppressor class. On the contrary, as the weeks of her captivity passed (some of which she spent blindfolded in a closet), she proved that she could despise the fascist insect just as vehemently as they did. DeFreeze, realizing that this development could be turned into a public relations coup, eventually put a weapon in her hands and photographed her before the SLA’s emblem of a seven-headed cobra. Then he enlisted his unlikely new recruit to help him rob a bank.

"American Heiress: The Wild Saga of the Kidnapping, Crimes and Trial of Patty Hearst" by Jeffrey Toobin (Doubleday)

Hearst’s exploits as a fugitive outlaw (she eventually adopted the nom de guerre “Tania,” after one of Che Guevara’s comrades) ended up lasting about a year and a half before her capture on Sept. 18, 1975. Over the course of those months, she actively participated in two bank robberies, a street-corner shootout, a carjacking and a series of bombings; she also watched on television as six of her SLA associates (including one who had become her boyfriend) perished in a ferocious and chaotic ambush in Los Angeles — “the biggest police gun battle ever to take place on American soil,” according to Toobin. The fact that Hearst and the other surviving SLA members were able to elude capture for so long is testimony not only to FBI impotency (few people would even speak to agents who came to their doors), but also to the remarkable willingness of so many ordinary citizens to hide and assist a fringe political group intent on violence. At one point, DeFreeze and two SLA disciples even went door to door in the Western Addition neighborhood of San Francisco, seeking allies among total strangers. Amazingly, they found some, and even those who refused to help them never reported the encounters to anyone in authority.

In “American Heiress,” Toobin, a staff writer at the New Yorker and a senior legal analyst at CNN, spins this complex chapter of recent history into an absorbing and intelligent page-turner. I do wish he’d provided more detailed and extensive endnotes, and that he’d done less marveling at the ineptitude and ideological confusion of the SLA and more explaining of why its message found such a sympathetic audience in the anti-establishment climate of the mid-70s. But his overall assessment of Hearst’s behavior is valid.

As Toobin sees it, Hearst (who refused to cooperate in the publication of this book) was a rational actor at every step in her ordeal. She embraced her captors’ cause not because she was too frightened to resist (as her lawyers later argued in court) but because eager cooperation with them was in her best interests at the time. So too was eager cooperation with law enforcement after her arrest, when she readily turned against her former cohorts to lighten her sentence. In each case, the betrayals made hard-headed, practical sense. As Toobin explains it: “In the closet, she became a revolutionary; in the jail cell, she became a Hearst.”

American Heiress
The Wild Saga of the Kidnapping, Crimes and Trial of Patty Hearst

371 pp. $28.95.