The eyes of John F. Kennedy's killer are not unkind. It's a peculiar, if quiet, revelation to make here, in his company. The killer resides in a federal correctional facility — a classified location that's at least a quarter-mile underground, and presumably miles from anywhere important. The facility is constructed from concrete amalgams and transparent materials so secret and durable, they don't even have a name. In the event of a global nuclear holocaust, a government contractor once said, only two things will survive: "the cockroaches and that guy."

He was called "The most dangerous man in the world" by President Lyndon B. Johnson, five decades ago.

His eyes are blue. His face is slender, deeply lined, made longer still by a natural frown. Still, he appears younger than most men his age. He's presumed to be 80 years old.

According to the correctional officers here, Kennedy's killer is a voracious reader. This seems true. More than a dozen books pepper the prisoner's spartan cell. Most are nonfiction books about social issues, such as Trish Tilby's recent expose, District X. But a few novels are present, including a dogeared copy of T.H. White's The Once and Future King.

You won't find a tablet computer or e-reader here, of course. There's nothing with a conventional circuit board or metal enclosure within a half-mile radius of this place.

More than 1,000 books — and very likely a thousand essays — have been written about the Nov. 22, 1963 assassination of President Kennedy. Nearly all have investigated the lives of people like Lee Harvey Oswald and Jack Ruby. Most have criticized the findings of the Warren Commission, the task force appointed by President Johnson to investigate the Kennedy assassination.

These critics insist the Warren Commission's final report was a rushed, inadequately researched frame-up. Nearly all proudly provide their own conspiracy theories about the events on that dreadful day in Dallas. And most insist that the man here — the man convicted of killing the president fifty years ago — is innocent.

Erik Lehnsherr. The man who calls himself Magneto.