Dickie was killed during Christopher's infancy, right outside the house while bringing TV trays home. In 2002, Tony Soprano told Christopher that Dickie's killer was Detective Lt. Barry Haydu, who had just retired from the force. Tony delivered Haydu to Christopher Moltisanti as a part of his process of bonding Chris to him and slowly easing him up the family hierarchy. However, when confronted by Christopher, Haydu denied ever having heard of Richard Moltisanti and claimed that someone was "obviously" setting him up. Later Haydu inadvertently admitted knowing Dickie Moltisanti by stating "Look, whoever told you I had anything to do with his death is lying!" before Christopher mentioned his father's death.
Haydu's last words may have been “I’m sorry," however that was possibly a line from the television in the background. Although, Magnum PI, a popular 80’s cop show starring Tom Selleck, was on the television and the dialogue didn’t call for someone to yell out “I’M SORRY” repeatedly. It is therefore up to interpretation as to whether the line came from Haydu or the television.
Tony Soprano remembers Dickie as a "stand up guy" and describes a lot of his positive qualities to Christopher. Dickie once took on a whole crew from New England and brought the war home to their turf. Tony also remembers that Dickie was killed because of a beef with Jilly Ruffalo, a man he was in prison with. Jilly murdered Dickie's cell mate and Dickie gouged out his eye in revenge.
According to Christopher, Dickie also struggled with problems of alcoholism and drug addiction.