Directly across the elevators on the 6th floor of the Manhattan District Attorney’s Office is a large wall—a montage of giant-sized newspaper articles spanning decades. The headlines and articles are about famous cases the office has handled. One of them is an almost life-sized photo of Mark David Chapman when he was 25 years old. The photo was taken soon after Chapman’s arrest for the murder of John Lennon. He shot Lennon four times outside Lennon’s residence at the famed upper west side apartment building called the Dakota. Yoko Ono was at Lennon’s side at the time. It was December 8, 1980. That life-sized photo of Chapman and all those historical articles were my view, as I stepped on and off the elevators for almost a decade at the DA’s office. Chapman murdered Lennon six years before I became an…