The Candidate

 

A high-profile, young woman is murdered. Despite evidence from eyewitnesses, DNA tests, and the retrieval of the murder weapon, the police is without a lead in the case for most of a year - until a completely unexpected observation is made.
 

That starts an accelerating cat-and-mouse game that takes place in both the real world and in the digital world, and it culminates when the murderer is trapped in a digital cobweb.