Matz 
Killer, The: Affairs of the State #1 (of 6) [PDF ebook] 

Caught and put to work as an on-call assassin for the French government, Killer has to adjust to working with a handler, a partner, and living life as a civilian. An underhanded target, a City Hall employee, leads Killer and his partner, Nicolas, toward a sinister web of city-wide corruption. But while Nicolas assures Killer that it’s all for the greater good, will Killer ever be able to get back to his nihilistic lifestyle, free from debt and government associations?