100 Bullets Vol. 13 Wilt (2009) Vertigo Paperback Book

This dark and intriguing Eisner Award-winning series features a mysterious agent named Graves who approaches ordinary citizens and gives them an opportunity to exact revenge on a person who has wronged them. Offering his clients an attaché case containing proof of the deed and a gun, he guarantees his "clients" full immunity for all of their actions, including murder.