We uncover how even when a professional hitman attempted to hide his identity from CCTV cameras, a forensic analyst used their expertise to help police build a case against a child killer. As pressure mounted on Merseyside Police to solve the shocking murder of nine-year-old Olivia Pratt-Korbel in 2022, detectives explored all avenues to catch the killer. All they have is grainy CCTV imagery of a dark-clothed gunman wearing a balaclava just before and after the shooting. A breakthrough comes in the form of a tip-off — the name Thomas Cashman is passed on to police as the man who murdered Olivia. Police enlisted digital analyst Tessa Macklam to help detectives prove that Cashman was the gunman seen on CCTV. Tessa's painstaking work examining 40 items of video over the course of two weeks eventually connects Cashman to the murder, solving one of Liverpool's most upsetting and notorious crimes. In June 2015, an amazing discovery was made in Herefordshire. Amateur metal detectorists unearthed a stash of ancient coins and jewellery worth potentially millions. But instead of declaring the precious find to the authorities, as the Treasure Act demands, the treasure hunters donated just a small fraction of the haul, and attempted to cash in on most of it through black market contacts. It was an unusual investigation for the police, and they called in expert witness Dr Gareth Williams, The British Museum's Anglo-Saxon coin specialist, who was tasked with comparing some of the coins donated to a museum in Wales with those allegedly sold on the black market. Gareth's careful analysis helped prove that both sets of items had been part of the same treasure hoard, leading to jail sentences for the pair involved.