Check out Work Done For Hire by Joe Haldeman, avaialble January 7th 2014 from Ace Hardcover.
Wounded in combat and honorably discharged nine years ago, Jack Daley still suffers nightmares from when he served his country as a sniper, racking up sixteen confirmed kills. Now a struggling author, Jack accepts an offer to write a near-future novel about a serial killer, based on a Hollywood script outline. It’s an opportunity to build his writing career, and a future with his girlfriend, Kit Majors.
But Jack’s other talent is also in demand. A package arrives on his doorstep containing a sniper rifle, complete with silencer and ammunitionand the first installment of a $100,000 payment to kill a bad man.” The twisted offer is genuine. The people behind it are dangerous. They prove that they have Jack under surveillance. He can’t run. He can’t hide. And if he doesn’t take the job, Kit will be in the crosshairs instead.