The Blooding by Joseph Wambaugh

Fifteen-year-old Lynda Mann's savagely raped and strangled body is found along a shady footpath near the English village of Narborough. Though a massive 150-man dragnet is launched, the case remains unsolved. Three years later the killer strikes again, raping and strangling teenager Dawn Ashforth only a stone's throw from where Lynda was so brutally murdered. But it will take four years, a scientific breakthrough, the largest manhunt in British crime annals, and the blooding of more than four thousand men before the real killer is found.