Author/cop Dillman (Unholy Matrimony, 1986) here recounts how in 1976 he tracked--and caught--the murderers of two federal witnesses. Just 48 hours before the trial of New Orleans heroin lord David Sylvester, key witnesses Eddie Smith and Paulette Royal turn up dead in a Howard Johnson's in New Orleans. Young detective Dillman arrives at the grizzly scene only to find a ""Who's Who of New Orleans criminal justice""--no surprise, with the viability of the federal witness program at stake. Since the New Orleans Police Department (NOPD) assigns cases purely on a take-turns basis, 29-year-old Dillman takes charge under the nerve-wracking scrutiny of NOPD brass, the FBI, and drug-enforcement agents. A survivor of the HoJo shootout (an innocent guest shot in the head but not seriously wounded) describes two triggermen and one ""sissy"" scout, so Dillman dresses like a pimp and cruises the transvestite part of the French Quarter tracking down a contact called ""Stick,"" who leads him to the ""sissy"" Cris--one of the tough transvestite junkies Sylvester uses as runners because cops leave them alone. Cris strikes a deal and spills all. A day later, one triggerman is caught; and based on his and Cris' testimony alone, D.A. Harry Connick decides to go ahead with a murder trial against Sylvester--with a conviction being the only hope of saving the witness program. Justice triumphs, and Dillman's a hero. Dillman's false modesty grates, and the trial recapitulation proves a slack windup; but overall this is a riveting, nitty-gritty account of police work under pressure.