Silent Witness is a British crime drama television series produced by the BBC that focuses on a team of forensic pathology experts and their investigations into various crimes. The series was created by Nigel McCrery, a former murder squad detective based in Nottingham. Since its initial release on 21 February 1996, 29 series have been broadcast.
Amanda Burton starred as primary character Professor Sam Ryan before leaving the show during the eighth series. Since her departure, the series has featured an ensemble cast, which initially consisted of William Gaminara, Tom Ward and Emilia Fox and later on David Caves, Liz Carr and Richard Lintern alongside Emilia Fox. At the end of series 23, Carr and Lintern departed.
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 Onetvnz.co.nz/silent-witness/show-432523 and Prime in New Zealand, BBC First in South Africa and BBC America in the United States.
On 21 July 2026, the BBC announced that it was putting the programme's production out to competitive tender, with the corporation continuing to show the drama as well as retain all rights.
Series overview The main character in the original series was based on Professor Helen Whitwell, a forensic pathologist based in Sheffield, whom McCrery had known while serving as a police officer. The programme followed the activities of pathologist Sam Ryan, played by Amanda Burton, until she departed early in the eighth series.
There was 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, continued as lead characters following Ryan's departure, with Dalton replacing her as professor.
A new character, Dr Nikki Alexander (Emilia Fox), was introduced in mid-series eight, a forensic scientist based in Sheffield. While working as a forensic anthropologist, she appropriates facilities and software in the pathology department to analyse an Iron Age find, with the belated, bemused and begrudging approval of Dalton. Dr Alexander is able to assist in a set of cases being investigated by the team, because it transpires that she has "worked in forensic pathology in Johannesburg for six months" and is certified by the Home Office to practise. She eventually overcomes Leo's reluctance and, with Harry's support, is offered and accepts a position on the team.
Before the 16th series begins, Harry has left to accept a position in New York City. He is succeeded by forensics expert Jack Hodgson (David Caves) and his assistant Clarissa Mullery (Liz Carr). At the climax of the 16th series, Leo is killed in an explosion. His replacement, Dr Thomas Chamberlain (Richard Lintern), is introduced at the start of the 17th series.
Although the show focuses heavily on areas of pathology, the police also have a presence in each case. During later series of the show, detectives and investigators tend to differ from episode to episode, with guest artists appearing in these roles. However, during the early years of the show several characters appeared regularly to investigate each case.
Location The first three series are set in Cambridge. The setting changed to London from the start of Series 4. From Series 6, the setting moved to the Lyell Centre, the Pathology Department of UCL. The programme remained in an academic setting until the end of Series 16 when the Lyell appeared to have become separated from the university and operated as a stand-alone institution. In 2023 it was announced that production for Silent Witness would be moving to Birmingham. This was reflected in the show at the end of Series 28, with Nikki accepting an offer to set up a new forensic centre in the city along with her team. From Series 29, the show was set at the Sir William Bowman Centre of Excellence in Birmingham.
Format Each series is typically made up of a series of two-part stories. The first nine series generally featured eight episodes (four two-part stories), except that series 4 and 5 each featured just six episodes (three two-part stories); this was increased to ten episodes (five two-part stories) from the tenth series onwards, except series 12 and 15 which each featured 12 episodes (six two-part stories). The 25th series, broadcast in 2022, introduced a new format consisting of one story in six episodes, but the format reverted to five two-part stories from the 26th series onwards.
International recognition In 1998, the writer John Milne received an Edgar Award from the Mystery Writers of America for the second series episode "Blood, Sweat and Tears". In the United States the series airs during 'Mystery Monday' on BBC America.
Music The theme music from series 2 onwards is entitled Silencium and is performed by John Harle. The arrangement, for chamber orchestra and soprano saxophone solo, was first performed publicly as part of the Canterbury Festival on 22 October 2011. The vocal section is performed by Sarah Leonard.
Critical review An episode first broadcast in April 2012 attracted criticism for its violent and sadistic content. There were 632 complaints made about the fifteenth-series episode Redhill, written by Ed Whitmore, which included a scene depicting a sadistic sexual and murderous attack. The BBC was censured by the editorial committee of the BBC Trust, which said in its report:
The BBC had responded to the initial criticism of the episode by saying that it took its responsibility to its audience "extremely seriously" and always tried to "strike the right balance between compelling drama without being unnecessarily graphic". It said that "The final scene was not an attempt to gratuitously shock the audience;... We acknowledge that certain scenes may have been challenging, but we filmed and presented them in such a way as to make sure that although as a viewer the implication was there, it was never actually shown."
Episodes
Characters
Overview ActorCharacterSeries1234567891011121314151617181920212223242526272829 Amanda Burton Sam Ryan colspan="8" colspan="16 " colspan="1" colspan="4" John McGlynn Tom Adams colspan="1" colspan="28" Clare Higgins Helen Farmer colspan="1" colspan="28" William Armstrong Trevor Stewart colspan="1" colspan="2" colspan="28" Ruth McCabe Wyn Ryan colspan="1" colspan="1" colspan="1" colspan="26" Mick Ford Peter Ross colspan="1" colspan="1" colspan="28" Nick Reding Michael Connor colspan="2" colspan="2" colspan="25" Mark Letheren Rob Bradley colspan="2" colspan="1" colspan="26" William Gaminara Leo Dalton colspan="5" colspan="11" colspan="3" colspan="1" colspan="9" Tom Ward Harry Cunningham colspan="5" colspan="10" colspan="14" Emilia Fox Nikki Alexander colspan="7" colspan="22" David Caves Jack Hodgson colspan="15" colspan="28" Liz Carr Clarissa Mullery colspan="15" colspan="1" colspan="7" colspan="6" Richard Lintern Thomas Chamberlain colspan="16" colspan="7" colspan="6" Jason Wong Adam Yuen colspan="23" colspan="1" colspan="5" Genesis Lynea Simone Tyler colspan="23" colspan="2" colspan="4" Alastair Michael Velvy Schur colspan="25" colspan="2" colspan="2" Aki Omoshaybi Gabriel Folukoya colspan="25" colspan="2" colspan="2" Rhiannon May Cara Connelly colspan="23" colspan="2" colspan="2" colspan="2" Maggie Steed Harriet Maven colspan="27" colspan="2" Francesca Mills Kit Brooks colspan="27" colspan="2"
Main Sam Ryan (Amanda Burton) – series 1–8, 25. Sam originally lived and worked in Cambridge, but moved to London at the end of series three after she was offered the job of professor at a university. Sam departed and returned home to Northern Ireland in the second episode of series eight, "A Time To Heal", in which a member of her family became a suspect in a murder case. At the end of Series 24, in a brief mid-credits scene, she is shown phoning Nikki Alexander to ask for help. This leads into her reappearing in Series 25. Leo Dalton (William Gaminara) – series 6–16. Leo first appeared in the episode "The Fall Out", where he was a doctor. However, he was promoted to professor after former professor Sam Ryan left. In the episode "Ghosts", both his wife, Theresa, and his daughter, Cassie, are killed in a car accident. He began a relationship with fellow professor Janet Mander in "Death's Door", but ended their relationship in the episode "Redhill". Leo often took a strong opinion on cases and became emotionally involved. He died in the series 16 finale "Greater Love", when he sacrificed himself to save many others from a terrorist bomb explosion. He briefly appeared in a flashback in the last episode of series 20. Harry Cunningham (Tom Ward) – series 6–15. Harry started out life as a junior doctor, who worked as an apprentice to Sam and Leo. However, he soon qualified as a pathologist, and has worked on equal footing with the team for a number of years. Harry was single, and lived alone, but has had several romantic relationships, including an ongoing 'will they-won't they' relationship with his colleague Nikki. Harry left the team to accept a professorship in New York at the end of series 15. As this was decided after filming was completed, and the stories were reordered, with "And Then I Fell in Love" airing last, where it was originally scheduled as the second episode, his departure was never on screen. Nikki Alexander (Emilia Fox) – since series 8. Originally appearing in the episode "Nowhere Fast", Nikki was originally assigned to the Lyell Centre to defuse the tension between Harry and Leo after Sam's departure. However, Nikki soon became a permanent fixture within the team, and although she features more prominently in the series, holds a lower rank in pathology than Leo. Despite her native home being South Africa, Nikki regards the United Kingdom as her second home, as the reason for her departure from the country lies solely in the hands of her father, Victor, as explained in the episode "Double Dare". Nikki often flirted with colleague Harry, and even invited him to stay at her house after his flat blew up in an explosion. Nikki and Harry were in an ongoing 'will they-won't they' relationship until he left in series 15. As well as this, she developed a close relationship with Leo and looked up to him as a father figure. As Leo and Harry gradually left, Nikki has since become the series' central character. She starts a relationship with Jack in series 25. They marry in series 28. Jack Hodgson (David Caves) – since series 16. Before his arrival at the Lyell Centre, Jack was a forensic scientist for the police, working on regular murder investigations. However, when he is called out to the scene of a man's suspicious death in "Change", both Nikki and Leo spot his potential, and looking for a senior colleague to replace Harry, decide to offer Jack a job as the centre's forensic expert. Jack is close friends with colleague Clarissa Mullery, whom he invites to work with him at the Lyell Centre, much to Leo's surprise. In his spare time, Jack is a cage fighter, and splits his home life between forensic research and training for his next fight. From series 25 he has a relationship with Nikki. They marry in series 28. Clarissa Mullery (Liz Carr) – series 16–23. Clarissa is Jack's personal lab assistant, who first appears in the episode "Change", when Jack invites her to work at the Lyell Centre with him, much to Leo's surprise. She is disabled by an unspecified condition and uses an electric wheelchair. She has a very cheeky side, making a quip at Leo after he fails to recognise her when she first arrives. Clarissa had clearly worked for Jack for a long period of time before his appointment at the Lyell Centre, but the exact period of time is unknown.