The Bounty Hunter by Jasper T. Scott

Cade Korbin was a member of the Coalition’s elite special forces until he was scapegoated and dishonorably discharged.
Now he hunts the galaxy’s worst lowlifes for a fee, and the only orders he takes are his own. But when his past catches up with him, Cade is forced to fight for more than just credits.
This time, he’s in it for revenge.