In this first episode Sir Trevor gains access into the notorious crime museum dubbed the ‘black museum', home to body parts, nooses and murder weapons, as well as unearthing police disciplinary records dating back to 1829. Sir Trevor also finds out about early policing forensics, DNA and fingerprinting, and early surveillance techniques, first unearthed when police were trying to identify suffragettes. Trevor also learns how the force proved the crimes of serial killers Dennis Nilsen and ‘The Acid Bath Murderer'.