Murder games.
(Book)

The next hand he deals you...may be your last. A serial killer is loose on the streets of Manhattan. His victims appear to be total strangers. The only clue that unites the crimes is the playing card left behind at each scene that hints at the next target. The killer, known in the tabloids as The Dealer, is baiting cops into a deadly and scandalous guessing game that has the city increasingly on edge. Elizabeth Needham, the gorgeous, tenacious cop in charge of the case turns to an unlikely ally--Dylan Reinhart, a handsome and brilliant professor whose book turned up in connection with the murders. As the tabloid frenzy over The Dealer reaches a fever pitch, Dylan and Elizabeth must connect the clues to discover what the victims have in common before The Dealer runs through his entire deck.