Silent Witness is a British television crime drama series, produced by the BBC, which focuses on a team of forensic pathology experts and their investigations into various crimes. First broadcast in 1996, the series was created by Nigel McCrery, a former murder squad detective based in Nottingham. He later went on to create the hit series New Tricks, with writer Roy Mitchell. Since 1996, twenty series of the programme have been broadcast. Amanda Burton originally starred as primary character Dr. Sam Ryan, before leaving the show during the eighth series. Since, the series has featured more of an ensemble cast, currently consisting of Emilia Fox, David Caves, Liz Carr and Richard Lintern. The programme is broadcast in more than 235 territories, including ABC in Australia, Showcase and the Knowledge Network in Canada, KRO in the Netherlands, TV One and Prime in New Zealand, and BBC America in the United States. Twenty years after its inception, Silent Witness continues to achieve good audience ratings; in 2011 Series 14 attracted an average audience of nine million viewers.