Name: Mark David Chapman
Crime: Video didn't kill this radio star; Mark David Chapman did. On December 8, 1980 he fatally shot John Lennon in front of the singer's New York city apartment building (the Dakota, also famously the location for Roman Polanski's creepfest Rosemary's Baby)
Where are they now? Attica. Yesterday its parole board denied him his freedom a fourth time, noting the "bizarre nature" of his crime. (Also, Chapman is regularly flooded with hate mail in prison, and it's thought that releasing him would essentially constitute a death sentence.)
Mark's lit picks: After the shooting, he calmly seated himself on the sidewalk and began reading The Catcher in the Rye. (He was arrested "without incident.") Echoing Catcher's protagonist, Holden Caulfield, he famously accused Lennon of being a "phoney."

john-hinckley.jpgName: John Hinckley, Jr.
Crime: The near-assassination of then-president Ronald Reagan on March 30, 1981, outside a Washington hotel.
John's favorite movie: 1976's Taxi Driver, about a man plotting the assassination of a political candidate. But Hinckley claims he wasn't just imitating the film's psycho-killer protagonist, Travis Bickle (Robert DeNiro), instead he had developed a serious obsession with co-star Jodie Foster. After creepily stalking her on and off for years, he decided the best way to impress her would be to kill a sitting president, thus making himself an historical figure, and -- to his mind, at least -- her equal.
Where are they now? Hinckley was judged not guilty by reason of insanity, sparking nationwide anger and prompting several states to rewrite the rules of their insanity pleas. He's been chillin' like a villain at St. Elizabeth's Mental Hospital in D.C. for the last 25 years, and recently has been judged safe enough to be allowed supervised trips outside the hospital to visit his elderly parents. He was disciplined after one such trip in 2000, however, after smuggling Foster-related materials back into the hostpial.
Fun facts: Hinckley was reportedly inspired by celebrity-killer Mark David Chapman, to whom he bears an uncanny resemblance.

Sirhan_Sirhan.gifName: Sirhan Sirhan
Crime: The murder of Robert F. Kennedy in the kitchen of Los Angeles' Ambassador Hotel on June 5, 1968.
What made him do it? God knows. Though the Palestinian-born Sirhan cited Kennedy's support for Israel's 1967 Six-Day War, he obsessively rants that "Kennedy must die" in diary entries which predate that event. As is seemingly true of most high-profile crimes these days, some believe the CIA was involved, claiming that Sirhan was brainwashed by their top-secret MKULTRA mind-control program, and under hypnosis at the time of the shooting. (Sirhan claims that he has complete memory blackout of the event, and even hypnosis therapy has not been able to elicit any details of the killing from him.)
Where are they now: the Corcoran State Prison in California, along with Charles Manson and serial machete-killer Juan Vellejo Corona.