Not Without Proof — Kay David

Staying alive is all the proof he needs

Stratton Santana was the black sheep of The Operatives, an elite group of hired assassins. But a botched assignment forces him underground, and no one but the desperate will hire him...until an international diamond cartel needs a killer to stop a killer. Dealers are turning up dead in South America -- the latest victim in a Rio de Janeiro hotel room. It looks to Stratton like the work of The Operatives. Jennifer Martinez, the slain dealer's assistant, is the next target, and Stratton must protect her. But it's nothing personal. Stratton is no hero -- until an attempt is made on his own life, and he realizes the cartel has set him up.

Now Stratton has no choice but to draw Jennifer into his dark world of high-stakes murder and intrigue. They're on the run -- in a race against time to bring justice down on the cartel...before they bring him down.