The character Sam Siegel, murder victim and co-owner of the Sapphire Coast casino, is a reference to Benjamin 'Bugsy' Siegel, owner of the Flamingo Hotel and driving force behind the development of the Las Vegas strip.
Richard Burgi and Nathan Fillion came face to face once before when Nathan played Malcolm Reynolds in Joss Whedon's Firefly; Burgi played Lieutenant Womack, a ruthless bent cop.
The episode title references the Elvis Presley song of the same name. When Castle, Ryan, and Esposito are thrown out of the casino in Atlantic City, they sneak back in wearing Elvis disguises.
Guest stars Jeffrey Vincent Parise and Robert Burgi both appear on "General Hospital".
Jeffrey Vincent Parise played mobster Tom Moretti. Whether coincidental or by design, he is made to look very similar to real life "Public Enemy #1" John Dillinger.