An American Killing

by Mary-Ann Tirone Smith (1998)

A thriller set in Washington D.C. and the fictional town of New Caxton, Rhode Island. From Amazon.com:

A bestselling true-crime author, wife to a Washington insider, Denise Burke knows the facts behind the rumors, the stories behind the scandals. Now Owen Hall, a charismatic congressman, urges her to investigate a triple murder case that may have led to a wrongful conviction. But as she begins to penetrate the fateful events surrounding the years-old homicide, Hall suddenly begs her to stop. Yet Burke is in too deep. The stakes reach a deadly level when Hall dies in flagrante with a D.C. call girl—and Burke uncovers a chilling connection. Desperately pursuing a story of secrets, sex, and blood—not for profit, not for fame, but for her very survival—Burke exposes the terrifying truth about the most monstrous crime of all.