"Average Homicide Cost Is $17.25M, Study Concludes"

FindLaw has this story from Iowa State University. On the methodology:

An overwhelming majority of this high sum is the result of the amount of money citizens would be willing to pay to prevent future crime. The study also used the same formula to determine the costs of other crimes: rape ($448,532), armed robbery ($335,733), aggravated assault ($145,379), and burglary ($41,288).