Nearly a decade after the abuse of vulnerable girls in Oxford began to be addressed, following years of negligence by police and social services, the last of the so-called Operation Bullfinch trials has ended. How did the sex offenders at the centre of the city’s depraved underworld finally come to face justice? Oxford, 2011. For nearly a year detectives have been receiving reports of girls disappearing, some as young as 13, only to return days later, refusing to tell anyone where they had been. Sometimes they would be bruised, bleeding and half-naked. For the past few months a Thames Valley Police team has been investigating the cases, but making little headway. But in the early hours of 14 November, the man leading the small group, Det Insp Simon Morton, made a connection that would spark the biggest criminal investigation in the city’s history. The senior investigating officer said he had just finished debriefing a surveillance team when the “penny dropped”. As he sat in the police briefing room and stared at the names of suspects written on a whiteboard, Mr Morton suddenly realised he wasn’t looking merely at a set of sexual predators, but a highly organised crime group. “I started scribbling like mad,” he said. “In honesty, I was annoyed I hadn’t seen it before – it was so bloody obvious.”