On the night of Oct. 19, the Yale Bookstore played? host to the final act of a drama that has played itself out for nearly 40 years. Warren Kimbro — convicted murderer, ex-felon and, according to a new book by Paul Bass and Douglas W. Rae, a changed man — offered a final apology.

“Murder in the Model City: The Black Panthers, Yale, and the Redemption of a Killer,” Bass and Rae’s fascinating new book, tells the story of the murder of 19-year-old Alex Rackley, a Black Panther party member suspected of becoming an FBI informant, and then traces the murder’s social, cultural and political consequences.

One night in 1969, Kimbro drove with three other men from a New Haven apartment on Orchard Street to the Coginchaug River in the small town of Middlefield, Conn. The men, all members of the Black Panther party, then walked to the edge of the water. Before the foursome returned to the car, Rackley would be dead, the vision and import of the Panther party at large would be thrown into question at the local and national levels and the lives of all the men involved would be forever changed.

Last Thursday, another character re-entered the story at a reading given by Bass and attended by Kimbro. George Edwards, former Black Panther and current activist, claimed that he, too, was supposed to be killed because he had refused to participate in the torture and murder of Rackley. Edwards managed to escape, but he was tortured and held at gunpoint before doing so.

Edwards stood up after the reading and demanded an apology from Kimbro, a demand which was neither unexpected nor unwarranted, Kimbro said.

“He had asked for a public apology,” Kimbro said, “and I don’t have a problem with that.”

And though it represented a plot twist not chronicled in their exhaustive book, Kimbro’s quiet acceptance is the sort of turn that Bass and Rae highlight in their new book. For the authors of “Murder in the Model City,” the horrible events of 40 years ago and the power of one man to change his life in the face of them go hand-in-hand.

Beginning with the days leading up to the murder, “Murder in the Model City” traces the story of Alex Rackley, the 19-year-old victim accused of leaking secret party information to the FBI. It examines the internal conflict that plagued the Panthers during the late 1960s. And, most dramatically, the book depicts the outrage and violence that gripped the New Haven community during the subsequent trial of nine Panthers and it explains how the Yale campus became a microcosm for the country’s larger racial unease.

Bass and Rae, both longtime residents of the New Haven area, insist that the crime and the famous Mayday protests which followed it remain vividly imprinted in the psyche of the community.

“For people who were in the area at the time and still live here, the event remains pivotal,” Bass said in an e-mail. “Everywhere I’ve spoken about the book around here, everyone wants to tell his or her story — staring at the muzzle of a tank in the Southern Connecticut State University parking lot, for instance, or waiting with a National Guard unit, or just seeing these wild people on the streets.”

The book is at its strongest when describing narrative details like these. On page after page, Bass and Rae are able to catalogue minutiae that paint a picture of an anxious city on the brink of self-destruction and of a campus that served as the locus for the protests and furor that accompanied the trials.

These small details also ensure that none of the larger-than-life personalities who make cameos in the narrative — Panthers founder Bobby Seale, Yale President Kingman Brewster, even former first lady and New York Senator Hillary Rodham Clinton LAW ’73 — seem like overblown caricatures.

And it is this insistence on the concrete and specific that might serve as the book’s most relevant message.

“The Rackley story poignantly shows the pitfalls into which both sides of the ideological divide — that remains with us today in the cultural war that grew out of that period — fall when they stop caring about the facts,” Bass writes.

Unfortunately, the book sometimes falters when it attempts to zoom out and distill lessons like this one from its story. At one point, gesturing toward the larger implications of their narrative, Bass and Rae write simply, “Nobody was very heroic back then, including the police.”

But the lesson seems obvious. Bass and Rae forget that the particular story they are telling could function as a more general warning about the dangers of shallow and divisive political discourse that marks our national climate. It seems unfitting that such a carefully constructed narrative cannot be used to greater effect.

But in the end, Bass and Rae have written a powerful and an important book. Though they are not explicit about their subject’s broader significance, it is clear from Thursday’s reading that the murder and its aftermath had a lasting impact on the New Haven story. This book is not an expansive attempt to derive easy lessons from the past, but it is a beautiful description of a crime that has haunted a town for 40 years and of a man who has been able to make amends with his past.

“New Haven’s [story] wasn’t unique in the civil rights era,” Bass said. “But it has its own story, as any city does — this one about a liberal city that tried harder than any other to bring about orderly, peaceful change and, at the moment captured in our book, confronted, painfully, the limits of liberalism.”

For Kimbro, the events of last Thursday represent the true denouement of the events chronicled in “Murder in the Model City.”

“We were not nice people back then,” he said. “But if you do something wrong, if you want to move past it, you have to admit it and apologize. To me, that’s the end of the story.”