Calling Cards

In a little over a week four women are brutally murdered; the frenzied hammer attacks leave the victims virtually unrecognisable. Not satisfied at bludgeoning the women to death, the deranged killer leaves his calling-card: a polaroid photograph of the victim protruding from their ruined mouths.
Suspects range from ex-partners, clandestine lovers, known crooks, and even bereaving teenagers are questioned and released.
After the second murder, school teacher, Allan Nixon visits his local police station. His confession shocks the constabulary. Weeks earlier his home had been burgled. Personal belongings had been stolen including dozens of polaroid photographs. The prints, some titillating, many lewd, all showed former lovers in various stages of undress. On the reverse side of the photographs, Nixon had scrawled personal details of the females, including a grading system according to their prowess in the bedroom.
Nixon is arrested. Forensics search his home and his vehicle. Teams of police trawl his gardens plus a wide area bordering his property. Friends and associates are interviewed, telephone records are checked. Nothing is found linking Nixon to the multiple deaths. Despite misgivings he is released from custody.
The following day a third victim - a seventeen-year old who attended Nixon’s night class - is found with injuries identical to the two previous murders. Numerous callers inundate police stations and all with the same message: Allan Nixon had been dating the youngster; Allan Nixon is the killer.
The teacher is re-arrested and spends a further night in the cells. Once again the S.O.C.O. squad descend on Nixon’s property. Despite further detailed searches of his home and property, police find no incriminatory evidence. Associates, past and present, are questioned thoroughly. When nothing untoward is discovered about the teacher, Allan Nixon is released.
Desperate for closure a surveillance team begins shadowing Nixon’s home. The exercise proves futile when, twenty-four hours later, a further victim is found.
A serial killer is at large.