In his lecture at the beginning, Jake Hunter (Michael Shannon) says that all known serial killers are male, with the exception to a recent case in the United States. This is a reference to Aileen Wuornos, who was arrested and charged in 1992 for murdering seven men.
Whose idea was it to bring her here? Bloody loose cannon!
When Parker-Jones walks into the police station, he is alone, but after the interrogation room door is closed, his lawyer suddenly appears.