“The little viper” is how MacDonald described Murtagh to the grand jury hearing his murder case. Later, to reporters, MacDonald called Murtagh “a berserk person, a middle-level bureaucrat run amok ... paid with taxpayer money to do this to me.”

When Morris’s “A Wilderness of Error: The Trials of Jeffrey MacDonald” came out in September, Brian Murtagh sat in the study of the Oakton home he shares with Margaret, his wife of 43 years, and read it cover to cover, all 500-plus pages. He found it credulous, manipulative, a Swiss cheese of strategic omissions. To assert this, he typed out a rebuttal — a legal brief, double-spaced, 14 pages long, with Roman numerals and alphanumerically labeled paragraphs. It is not light reading. Morris, Murtagh writes, “doesn’t explain how 60 pieces of the pajama top, including the ripped-off pocket bearing a contact stain in Colette’s blood, could be found in the master bedroom, as well as 30 seam threads. ... ” Murtagh didn’t file this odd document anywhere. He didn’t release it to the media. It was mostly for himself.

Almost from the start, investigators focused on MacDonald, whose account of the attack seemed to contradict the physical evidence: the locations of bloodstains and spatters and of torn fibers from his pajamas, and the lack of evidence of a furious defensive struggle. Although the doctor was initially cleared by a preliminary Army hearing — “insufficient evidence” — he was prosecuted in 1979 in federal court, where he was convicted after a six-week trial. The jury was out only six hours. The prosecution’s methodical use of circumstantial evidence had overcome a signal weakness in the case: The state never presented an entirely convincing motive.

The lurid crime was an international story that became even bigger with the publication in 1983 of “Fatal Vision,” the bestseller about the case by journalist Joe McGinniss; the book would lead to a TV miniseries and, later, to an excruciating spasm of self-examination by the media. The MacDonald murders had spawned a second Big Story.

From prison, MacDonald sued McGinniss for breach of contract, alleging that the writer had betrayed him. During trial and its preparations, McGinniss had been embedded with the defense team, ostensibly to write a book about an unjustly accused man. At some point, the writer became convinced of the doctor’s guilt but never told MacDonald, fearing he would lose the doctor’s cooperation. So, as he was ingratiating himself with the convicted killer, feigning incredulity over the verdict, encouraging MacDonald to send deeply self-revealing letters from prison, McGinniss was writing a book describing MacDonald as a narcissistic, psychopathic monster. McGinniss contends he behaved ethically in dealing with MacDonald under enormously difficult circumstances.