Silent Witness is an acclaimed BBC thriller series, focusing on a team of forensic experts and their investigations into various crimes. First broadcast in 1996, the twelfth series was broadcast from 1 October - 6 November 2008. The series was created by Nigel McCrery, a former murder squad detective in Nottingham. He later went on to create the hit series New Tricks with Roy Mitchell. The series was based on Prof. Helen Witwell, a forensic pathologist based in Sheffield. McCrery had known Helen while serving as a police officer. The series normally attracted around seven million viewers in the UK. In the United States, the show airs during 'Mystery Monday' on BBC America.

Overview

The programme originally followed the activities of a female pathologist, Dr Sam Ryan (who was promoted to professor part way through the series), played by Amanda Burton. However, Ryan's character departed early in the eighth series in 2004. There had been a succession of regular supporting characters, changing almost every series, but Dr Leo Dalton (William Gaminara) and Dr Harry Cunningham (Tom Ward), who were introduced in the sixth series in 2002, remained in the series and continued as lead characters following Ryan's departure, with Dalton replacing her as professor. A new character, Dr Nikki Alexander (Emilia Fox), was introduced to the team in the eighth series in 2004. She began as a palaeontologist, not a pathologist, and was originally enlisted by the team to help analyse bones. Alexander was later represented as having the necessary qualifications to fill the vacancy for a pathologist left by Professor Ryan, although she was initially stated to have a PhD in anthropology and not a medical qualification. She has, however, since been represented as medically-qualified.