Philip Kerr 
Philosophical Investigation [EPUB ebook] 
A brain-bending serial killer thriller from the creator of the bestselling Bernie Gunther books

London, 2013, and the city is battling an epidemic of serial killings — even with the widespread government use of DNA detection, brain-imaging, and the ‘punitive coma’. Detective Isadora ‘Jake’ Jacowicz is hunting a murderer, code-named ‘Wittgenstein, ‘ who has taken it upon himself to eliminate anyone who has tested positive for a tendency towards violent behaviour — even if they’ve never committed a crime. His intellectual brilliance is matched only by his homicidal madness.