Blowback - Mark L. Lester

Whitman is a psychotic religious killer who was caught by Inspector Morell a former seminarian, whose religious knowledge led to Whitman's capture. Whitman was tried and sentenced to death. However, he was rescued by a secret government group who want to make him an assassin, however, Whitman escapes and decides to get back at the people who tried to stop his mission, the jury, the judge, the district attorney, who's Morrell's ex-wife. Morrell recognizes the killings as Whitman's style but how could it be when he's dead. The man who recruited Whitman posing as an FBI agent claims that they are looking for a copy cat but Morrell finds it hard to believe that it could no one other than Whitman.