Jason Ray Forbus 
Contract Killing in the Information Age 

Everything there is to know about contract killing in a book that covers the mythical early origins of murder as a profession, to present-day availability of hit men on the open market.
A personal vendetta or self-driven interests are typical motives for pulling the trigger. In recent years, however, crime records have seen a staggering increase in the number of cases involving hired guns. This book explores why and how the phenomenon is growing to threaten all strata of a highly destablizied society.