Preview Clip: Victim Killed with Ryan's Old Gun in Castle Season 4, Episode 4: "Kick the Ballistics" Tweet October 7, 2011 by Samantha Leffler Related: Castle, Sneak Peeks , Richard Castle , Kate Beckett , Javier Esposito , Kevin Ryan , Season 4 Episode 4 Credit: ABC Turns out, the latest Castle vic was killed with Ryan's old weapon — the one that was stolen by the serial killer, 3XK.
