Killer at the Crime Scene

Police receive a call: a 21-year-old university student has gone missing. Friends report that after being turned away from a club, Libby Squire was put into a taxi and hasn't been heard from or seen since, and it's very out of character.

Humberside Police launch one of their biggest-ever missing persons searches, while digital forensic experts trawl though CCTV. Libby is captured walking away from her home address. The team continue to track her movements and notice something concerning – a male figure mirroring her movements on the other side of the road. He then approaches her and leads her to a car. The car is tracked to a playing field. Libby is not seen again, and a witness reports hearing a chilling scream around the same time.

Libby's disappearance prompts a number of women to come forward with disturbing reports of being watched, followed, or exposed to, by a man. Forensic experts link a number of the women's reports – leaving them in no doubt there is serial sexual predator in Hull, but with Libby still missing the team can't prove if she has fallen victim to the same offender.

Then a body is found in the Humber Estuary, and scientists use microscopic forensic evidence to unlock the case.

Police in Cornwall uncover a house of horrors: three bodies wrapped in bedsheets, hidden under a woodshed. The bodies are badly decomposed, police call in forensic experts to carefully recover the remains and begin formal identification.

The house belongs to the Ford family, Lesley and her four teenage children Sarah Jane, Anne-Marie, Craig, and Steven have been missing for almost a month. Forensics must determine if they are the bodies in the garden.

While a forensic odontologist looks at dental records, police uncover a web of lies and zero in on their prime suspect, chasing him down on Bodmin Moor. But despite a shock confession, the discovery of two further bodies in a potato field leads forensic experts to unravel the suspect's story, leaving the jury in no doubt the murders were carefully planned and acted out with clinical precision.

The discovery of a body wrapped in a shower curtain and buried in a makeshift grave in the garden of a Surrey home - and how the forensic investigation turned up a dark secret.

How the discovery of a woman's dead body in a playground led to the forensic analysis of a water bottle, linking the murder to a series of sexual assaults in the area.