On November 22nd, 1963, President Kennedy was shot at approximately 12:30 p.m. Nearly an hour and a half later, Oswald was in police custody, charged with assassinating the president. But Oswald's demeanor was puzzling to both the Dallas officials and to his own brother.

In a small interrogation room on the third floor of Dallas police headquarters, Oswald identified himself as "Hidell" to one of the first detectives who questioned him. Oswald proceeded to undergo hours of interrogation by homicide captain Will Fritz and District Attorney William Alexander. More than three decades later, Alexander remained extremely troubled by Oswald's curious behavior that afternoon.

"I would say that he was programmed," Alexander told me in a 1994 interview. "I don't know how many murderers, robbers, burglars, pimps and prostitutes I had talked to in connection with criminal cases—but Oswald's responses were not typical. They were completely atypical. He knew how to avoid a question, and knew how to get right back to you. One way of avoiding interrogation is to answer a question with a question. For the most part, that's what he did, or else make an unwarranted accusation [against his interrogators]."

Alexander continued, "A person's mind can be worked on, where they get an idea and won't give it up. Of course, everybody went 'ha, ha, ha' when I suggested that. It came to me within a few days, but nobody knew what I was talking about. But that guy was under control. It appeared to me that someone had coached him very carefully about how to handle himself in custody. It was as if he had foreseen and anticipated the situation he found himself in. That's my 'Manchurian Candidate' theory."

Also mystified by Oswald's attitude in custody was Frank Ellsworth, an official with the federal Alcohol, Tobacco and Firearms agency, who was called in by Captain Fritz to quiz Oswald about weaponry. As Ellsworth recounted it to me, "I tried to question him shortly after his arrest. But he just sat there with this very self-satisfied smirk on his face. Oswald appeared to be awfully pleased with himself, which struck me as incongruous for a man accused of assassinating the most popular president since Franklin Roosevelt. Particularly with the media out in the hall screaming and hollering like absolute jackals."

When Oswald's brother, Robert, visited him that weekend in his cell, he recorded in a diary: "All the time we were talking, I watched his eyes for any sign of guilt.... There was nothing there—no guilt, no shame, no nothing. Lee, finally aware of my looking into his eyes, stated, 'You will not find anything there.' "