In 1956, Captain Howard Finney, the head of the N.Y.P.D. bomb squad, dumped a satchel of evidence on a psychiatrist’s desk. For sixteen years, the police had been hunting a serial bomber who preyed on New York City. The nearly three dozen homemade explosives that the bomber had set off in public places—including Grand Central Terminal, Penn Station, and Radio City Music Hall—sowed a culture of fear more than four decades before terrorism became a daily worry. “Seldom in the history of New York,” the Associated Press wrote, “has a case proved such a torment to police.”

The N.Y.P.D.’s strong-arm methods—roundups, interrogation—had been unsuccessful in apprehending the bomber. In desperation, Finney sought the help of an eccentric, drug-addicted psychiatrist named James Brussel, who specialized in “the criminal mind.” What sort of person was the bomber, Finney wanted to know, and what wounding life experience led to his violent impulse? Brussel examined the forensic evidence and the unusual word choices that the bomber made in the letters that he sent to newspapers. The doctor compiled a portrait of the suspect that was later shown to be uncannily accurate, right down to the cut of the bomber’s jacket.

In the video above, the first in our “True Crime” series, Michael Cannell, the author of “Incendiary: The Psychiatrist, the Mad Bomber and the Invention of Criminal Profiling,” discusses the hunt to catch the bomber and the lasting influence of the case on both law enforcement and pop culture.