William Petersen and Marg Helgenberger only make cameo appearances in this episode as they were busy filming scenes for later episodes in the series. Ironically, "Ellie" became the first CSI episode to hit number one in the ratings.
The West wing aired season 2/15 "Ellie" on 21 Feb 2001, about 10 months before this show released. On CSI Ellie is brass' daughter, in the West Wing, Ellie is the president's daughter. In both shows, they are seen for the first time.
Catherine is absent due to her being away with Sam Braun, which is part of her ongoing personal life sub-plot story arc.
At the beginning,the con man holds different color casino chips,but when the cash in dealer(Anthony E.Zuiker),holds up the blue chip,blue isnt one of the color chips the con man was holding.