Silent Witness follows the work of forensic pathologist Dr. Sam Ryan, played by Amanda Burton. The series was created by an ex-police officer, Nigel McCrery - who has also published five Silent Witness novels based on the series
The pathologists investigate when a military helicopter crashes into a refugee detention center. Harry and Nikki actually witnessed the crash and were first on the scene but the case is complex since the center was Ministry of Defense property leased to the Home Office. The team is shocked at the conditions they find in the center and Harry, who has a close friend in the RAF, is shaken when a government Minister attributes the accident to pilot error.
The team is shocked when Leo Dalton's wife and daughter are killed when a fancy sports car careens out of control and smashes into a café. The police are puzzled by the cause of the crash but believe the driver may have been involved in a identity theft ring when they find several several passports and ID cards in the vehicle. Meanwhile, Nikki must perform urgent autopsies on two bodies found floating in the river.
Following a court appearance for drunk driving, Leo is required to perform unpaid work as a punishment, assisting AJ, a community worker on a run-down,largely black-occupied housing estate in South London. AJ is hoping to divert boys away from crime by encouraging them to do sports, and, though initially dismissive of Leo as a white intruder, comes to respect him after he has saved the life of Errol, a former gang member now anxious to keep his little brother Levi out of trouble. Errol has been stabbed in the leg by members of a gang from a rival estate and Leo stops him from bleeding to death. Earlier in the week a young girl called Shana Block was stabbed to death at a funfair and her murder recorded on a mobile phone. As Shana lived on the estate police sergeant Wallace involves Leo as a go-between with the suspicious residents. Also on the scene are Harry and Nikki, the latter dating Ryan, a young Scottish paramedic she met when called to the scene of Shana's death.