In Pursuit of the Past by Carolyn LaRoche

After adoption worker Ava Taft stumbles upon an abandoned baby that may have ties to her past, she finds herself with a target on her back—and only one person she can trust, despite his long-time anger at her.
For ten years, Detective Hudson Pierce let guilt push away the only woman he’d ever loved after the loss of his sister. When Ava shows up with a baby, a cryptic note hinting his sister may be alive, and two men trying to kill her, he has no choice but to put aside all the blame.

Can Hudson take them into his protection and put their past aside long enough to find out the truth about his sister, the baby, and the killers after Ava.. .before those killers silence them all for good?