A look at one of the most mysterious murder cases in recent years - the apparently motiveless shooting of his wife and baby daughter by 30-year-old Midlands-born computer engineer Neil Entwistle at their home in Massachusetts in 2006. The film has unique access to murder case files, plus testimony from friends, police and defence lawyers. It also provides the first credible explanation for the murder by an eminent forensic psychiatrist who believed Entwistle may have suffered from the autism-related condition Asperger's Syndrome.

• Mark Austin