The Quality of Mercy by Gilbert Morris

When tragedy strikes, will Dani Ross have The Quality if Mercy?
Successful sleuth Dani Ross faces her most harrowing challenge ever when Tommy Cain, an embittered parolee, threatens revenge against the Ross family.
Although drug-related crimes and acts of violence coincide with Cain’s release from prison, the police cannot pin anything on him. Dani is paralyzed by fear over the ex-con’s threats, especially as they target her family and friends. When tragedy strikes, Dani vows to go after Tommy Cain herself.
Undercover as Margo St. Clair and Flash Manti, Dani and her sidekick, Ben, shadow Cain and his cronies down dark alleys and into smoke-filled dives along Decatur Street in the French Quarter. The quest comes to a close in the murky waters of a swamp filled with alligators.