john lennon dead. >> former beatle john lennon was gunned down in front of his exclusive. >> ending the life of a folk hero. >> gunned down. >> the news ripped through the air in shock waves. john lennon shot and killed in the dakota apartment building. >> it was really shocking. >> 40 years old, john lennon of the beatles. how could he be dead? how could this happen? up aought city was in shock. not just people of my generation that grew up listening to their music in the 60s. just about everybody felt on so many levels it was wrong. >> it was terrible. just the way so many people didn't know john. felt. it just hit home with me much more because -- he befriended me. he didn't have to befriend me. >> in new york, cnn investigative reporter, has come up with some new facts about john lennon's accused killer. >> the killer was identified as mark david chapman, a