Breach of Trust (Berkley Prime Crime Mysteries) Reprint edition

On the night his wife and infant daughter died, attorney Jason Kolarich was awaiting a call from an informant. He blames himself not only for the deaths of his family, but for the informant's murder as well. Kolarich can't bring back his family, but he can find the person who killed the informant. And he discovers that his informant's murder was only the tip of the iceberg-and that exposing the truth will drag him into the fight of his life.