The Marshal (Harlequin Intrigue Book 1543)

His painful past is their present danger 

The last thing US Marshal Brent Thompson needs is distraction from his work. But distraction—in the form of a sexy Chicago investigator—is exactly what he gets. Jenna Hayward is as alluring as she is determined, driven to help apprehend the murderer who killed Brent's mother twenty-three years ago. With a shared mission—and a steadily rising attraction that jeopardizes Brent's resolve to stay unattached—the pair must work together to get answers…before the murderer makes them his next victims.