Jeremy Vine and Tina Daheley are once again live from the location of one of the UK's biggest unsolved cases. They also have the very latest developments on last week's appeals. This edition also features a special investigation into the recent spike in knife crime, particularly involving teenagers. Alison Cope, whose son Joshua was stabbed to death in 2013, explores why so many of Britain's youngsters are arming themselves with knives. Plus there is the inside story of how detectives caught a schoolboy killer. Double murderer James Fairweather was just 15 when he stabbed and slashed father-of-five James Attfield more than 100 times in Colchester in March 2014. Three months later, Fairweather went on to murder 31-year-old student Nahid Almanea, who was found stabbed to death on her route to university. The Crimewatch Update programme has been replaced with a new live digital platform linked to the show's website, which keeps audiences up to date with developments on the cases.

Jeremy Vine and Tina Daheley return with a special episode of Crimewatch dedicated to tackling child sex abuse. In light of revelations about the scale of non-recent abuse in football, Crimewatch has been granted unprecedented access to Operation Hydrant, the UK's national police operation tasked with bringing abusers to justice. Specialist detectives reveal how they are investigating these cases, sometimes decades after they took place. The programme also hears from the survivors about the suffering they have experienced and, for some, their sense of resolution when they see their abusers jailed. Jeremy and Tina are also joined by BBC Breakfast's Jon Kay, who broadcasts live from a call centre operating throughout the programme. Offering confidential help and support to victims of abuse, it is hoped this special episode will allow more victims to feel emboldened to come forward and tell their stories.