Malice at the Marina by Carol Ericson

He wants his missing sister back. She needs her escaped witness.

All the years Detective Billy Crouch has searched for his missing sister, she’s been in witness protection. Now she’s fled...with criminals in pursuit. And US Marshal Mia Romano must locate her before it’s too late. Joining forces, Mia’s focused on recovering her witness, while Billy just wants to keep both women safe. But the searing attraction he and Mia share may prove a distraction they can’t afford.