The Case of the 1973 killing of Joe Alon in the Washington, D.C., suburb of Bethesda ranks high in the Israeli and American annals of unsolved murders.Alon (born Placzek), who survived the Holocaust by being sent to England at the age of 10 by his Czech-Jewish parents just before the outbreak of World War II, immigrated to Israel in late 1948, joined the Air Force, and became an ace fighter pilot, tactician, and logistics expert. He attained the rank of colonel, and was posted to the Israeli embassy in Washington in 1970 as the air attaché, where he was responsible for the purchase of American equipment for the IAF.A popular man, he was gunned down late one night in the driveway of his home. The killer or killers fled, and the resultant police and FBI investigations, which appear in retrospect to have been less than thorough, turned up nothing. The Israelis showed little interest: when Alon’s late widow appealed to her husband’s senior defense colleagues, she was told, in so many words, to forget about it and move on.This response ensured, unsurprisingly, that she did no such thing, and she resorted to conspiracy theories (had her husband uncovered a plot by Israeli and American politicians to let the Egyptians score successes in the Yom Kippur War in order to swing Sadat into the American camp?) to explain the silence. Without progress in the case, these theories gained traction.The good news is that “Chasing Shadows” wastes little time in laying them to rest. Fred Burton, a vice president of the commercial global intelligence firm Stratfor, a former senior counterterrorism official with the State Department charged with protecting foreign diplomats, was interested in the Alon case partly because he grew up in Bethesda and was a teen at the time of the murder.He later writes that “I was not just solving Joe’s murder. I was solving the riddle of my own life’s path.” This cliché, the staple of so much pretentious inspirational literature, is one of the few phrases in this otherwise plainly written and intelligible book that strikes false. It is clear that Burton was sparked in the main by the professional challenge of solving such an old, cold case (though he seems to have been further motivated by sympathy for Alon and the dismal treatment meted out to his family). Indeed, much of the fascination of “Chasing Shadows” is being afforded a glimpse of the techniques used by security professionals to solve the long unsolved mystery.Despite being hampered by the destruction of the evidence gathered by the American law enforcement agencies (goodbye, DNA), Burton swiftly rules out the more lurid theories, as well as the jealous-husband theory: Alon was, it is broadly hinted, a ladies man. The killing, though, was professional, and Burton carefully analyzes the techniques used, as far as they can be reconstructed so long after the event. His solution? Black September, the 1970s Palestinian terror group. This seems odd, as it normally confined its attentions to Europe, but Burton amasses circumstantial evidence. During this period, Black September and the Mossad were waging tit-for-tat assassination campaigns, and the Palestinians’ modus operandi (a long period of surveillance beforehand and elaborate escape arrangements after the fact) fits what is known of the Alon killing.Further, the author claims that Alon was playing a double role in the US, that of a Mossad agent. This made him a natural Black September target as well as explaining the reluctance of the Israelis to press the matter. They were afraid that the Americans would discover what he was up to, and decided to bury the whole thing.Could it be true? Difficult to judge. It is surprising that the Mossad would have risked running as an agent a man with no prior experience of intelligence work and whose trustworthiness was of prime importance in nurturing the fledgling US-Israeli military relationship. Alon’s family remembers an odd piece of equipment at home, which Burton identifies as a Mossad device, and the late General Mordechai Gur, then the military attaché in Washington, interviewed by a police officer on the night of the murder, apparently made a startling admission that Joe Alon was indeed an agent. But memories are unreliable, and Gur’s statement never found its way into the official police report.To back his deductions, Burton relies on the other method of the security professional: squeeze all your intelligence contacts, colleagues, friends, and even enemies, for all they are worth. (Warning: do not try this at home.) He soon produces confirmation for his theory. Indeed, the story closes with a cryptic message on his Blackberry, which tells him that the Mossad has finally taken care of its unfinished business: the assassin has been nailed. Justice has been done.The problem is that in this John le Carré sub-world of agents with more than one interest to serve, statements can rarely be taken at face value: a difficulty the author properly concedes. Further, your average intelligence man is a shy and retiring sort of person, melting gratefully into the shadows at the earliest opportunity.Don’t even think of finding names here: they have been redacted, withheld to protect the informants, even (in one case) suppressed for legal reasons. No doubt this is justifiable, but a lot, perhaps too much, depends on whether you are willing to take what the author says on trust.Burton comes over as a straight-shooting blue-collar guy (aided by his co-writer John Bruning, a military historian responsible for the chapters on Israeli and American military aviation history), the salt of the American earth, or as he puts it “the kind of people who built America and kept it great.” Interestingly, there are more than a few hints that he believes America has broken faith with his type and class. But at least this reader is willing, at the close, to think his theory plausible: a possible solution, if not the only possible solution.And, nearly 40 years after Alon’s murder, this may be the best we will ever have.