Synopsis
Knife and gun crime is on the rise but prosecutions are falling as key witnesses are terrified of giving evidence - with good reason. Livvy Haydock explores the dark world of witness intimidation, and finds a sophisticated and highly effective system of menacing violence amplified and driven by social media. She meets gangsters who threaten `stitches for snitches', as well as families of witnesses who paid the price of telling the truth in court.