A wonderfully absorbing look at the lives and careers of two very different cops who happen to be cousins: one a former New York City detective, the other a longtime firearms specialist and chief of a Suffolk County crime-scene outfit. Suspense writer Cuomo (Trial by Water, 1992) is also a cousin of Al Della Penna and John Cuomo; the three grew up together in the Bronx. He intersperses lengthy narrativestyle interviews with his own comments and observations on the two men and the family. John, ""a tough, gruff street cop,"" tells his story with passion and humor. He became a cop, he says, because ""the NYPD was one of the few places where a high-school dropout from the Bronx would be judged on his readiness to work and learn."" A rookie in 1954, John was assigned to crime-ridden East Harlem, where learning his job meant becoming accustomed to poverty, drugs, and daily violence. He recalls numerous cases from his nearly 20 years in the Narcotics and Robbery division, from which he retired in 1974 after being arrested and suspended on bribery charges, of which he was later cleared. Al, ""a meticulous scientific investigator,"" discusses his 30 years at the Long Island Suffolk County police department with quiet, thoughtful restraint. As the department's chief firearms examiner, he was involved in several celebrated cases, including the 1974 murders of six members of the DeFeo family, which became known as the Amityville Horror. His detailed monologues on his methodical approach to crime scenes and lab work could serve as an instructive text for mystery and true-crime writers, as well as novice police officers. The author's deep background knowledge of his two cousins brings insight into their differing personalities, approaches to work, and attitudes toward the job. An odd mix of true crime and family history, but masterfully blended together.