'Battlestar Galactica's Tricia Helfer for 'Criminal Minds' finale Published Mar 26 2012, 16:47 BST | By Daniel Sperling Share Share Battlestar Galactica actress Tricia Helfer has revealed that she will guest star in the Criminal Minds season finale. The actress told TV Line that she is to play "a bad character" in the May 16 episode of the CBS series. © WENN / Judy Eddy © CBS It is known that the Criminal Minds season seven finale will be extended to two hours and focus on a hostage situation in a federal bank involving members of the main cast. The episode will also see Paget Brewster (Emily Prentiss) exit Criminal Minds for a second time. She was previously dropped from the show in June 2010, but returned for this season. Speaking in January, Brewster described her brief absence as "dumb" and "a mess". Criminal Minds airs Wednesdays at 9/8c on CBS. > CBS sets season finale dates: 'CSI', 'NCIS', 'Big Bang Theory', more Share ShareMore Cult Battlestar Galactica Tricia Helfer Paget BrewsterPrevious 'Mad Men' exec Matthew Weiner: 'Don Draper is genuinely in love' Next 'DWTS' William Levy denies Cheryl Burke romance: 'We're just dancing'