The Marshal’s Mobster by Este Holland

This witness is more than he seems.
Jericho Alvarado has been stuck babysitting a former mob boss in Alaska for months. He’d rather be hunting down fugitives with his fellow marshals, but Damian Corsetti is no ordinary witness. He made demands the District Attorney’s office had to meet or risk losing their star witness.
And having Jericho protect him was his biggest demand.
A former heavy hitter in the Vegas mafia, Damian knows all about the who’s who of Organized Crime. With a target on his back and so much at stake, it’s hard to know whom to trust.
When their cover is blown, they hit the road only to find out that Rio, Rake, and Carter have been kidnapped.
Together, Jericho and Corsetti, along with their most trusted friends, must work together to find them and bring down their enemies…
Or they’ll die tryin’.