Now Brianna's mother, Esther Ghey, speaks in-depth about her "beautiful daughter" and how the shattering loss has driven her campaign for change.
There are also exclusive interviews with friends and family as well as the detectives who worked on the case. Cheshire Police has given exclusive access to its investigation, including evidence and custody suite interviews with the two killers, who were caught within 28 hours.
Detective Superintendent Adam Waller recalls: "There were multiple stab wounds. The hairs on the back of your neck stand up."
Detectives reveal for the first time ho...