Being a retired Cambridgeshire police officer, I was interested to read this crime novel, however the plot is too far fetched in relation to how the police failed to conform to the Police and Criminal Justice Act, allowing the offender to go free. The police caution when an offender is arrested, is vitually the first law that officers must learn virbatim during their training. It is never forgotten. When interviewing an offender UNDER CAUTION, officers are reminded to again caution the offender at the beginning of the taped interview. Helen stole Peter's firearm and the police were trying to link the theft with Helen but no fingerprints or DNA were taken from his house where she had spent a night of intimacy with Peter.