Death Has No Dominion

Death Has No Dominion consists of the first and second episodes of Series 15.

Synopsis
The team investigates the brutal murder of a family, which they learn may be linked to a series of crimes committed by the same person over several years; meanwhile, Nikki struggles to come to terms with the death of her father.

Trivia

 * The killer in the episode, dubbed as the Wraith, is partially based on the real-life Phantom of Heilbronn. The Phantom of Heilbronn was a unknown female serial killer who only existed from traces of her DNA being found numerous crime scenes throughout Austria, France, and Germany between 1993 and 2009. Among these crimes were six murders, including the murder of police officer, Michèle Kiesewetter who was shot along with her partner as they were sitting in their patrol car on a lunchbreak in Heilbronn on the 25th April 2007.
 * While the murder of Officer Kiesewetter was considered to be the work of the Phantom, it was later revealed that her murder, and the attempt on her partner were committed by members of the German Neo-Nazi terrorist group, the National Socialist Underground who also had committed nine racial murders with a further 22 injured across Germany from the 9th September 2000 to the 6th April 2007.