In the Dark aka The Watcher

Lieutenant Jonathan Stride has never forgotten the case that made him decide to join the police force. Back in the 1970s, Laura – sister of Stride's girlfriend – was murdered. The obvious suspect was a vagrant, who slipped through the hands of the police, including Stride's detective hero Roy. Now, though, Stride's looking at the case in a new light. Tish Verdure, an old friend of Laura's, has come home, and she's certain that the killer was a local boy, now an attorney with connections at the highest level. Stride's soon convinced that there was a deliberate decision to direct the investigation towards a simple solution and away from Tish's suggested perpetrator, but he's also sure that Tish is hiding a secret about the past. A secret that could have shattering consequences – including a second murder…