Simpatico story of a narcotics detective who finds his teenage daughter selling drugs. Pat DeGregorio joined the NYPD in 1973 and was a standout patrolman, soon assigned to undercover work. His home life wasn't as smooth, however: He and his wife already had a daughter, but then a second child--a boy--had been born with a heart defect, and DeGregorio's wife began developing a serious drinking problem. The cop threw himself into his work, got a gold shield, and was assigned to a major heroin case in which he posed as an Italian pusher, working up a chain of dealers to $90,000 buys. Then, at age five, DeGregorio's son died on the operating table, and the cop was shattered. He moved out of his house, powerless over his wife's alcoholic hostility, leaving his daughter, Mary Anne, in her care. After several years of bachelor life, DeGregurio moved in with a woman detective, eventually marrying her. Here, veteran New York Times reporter Blumenthal (Last Days of the Sicilians, 1988) gives an excellent sense of police work with the glitz peeled off--the long shifts and grimy station houses; the petty martinets in command; the difficulties of married couples who are both cops getting some time together. When Mary Anne hysterically insisted that DeGregorio take her from her drunken mother's house, the cop helped his daughter move into the small apartment with his new wife. Soon, his wife discovered that Mary Anne was, at age 13, a daily drinker. But DeGregorio seemed to have a special blind spot about his daughter, even when his wife told him the girl was using drugs. He finally caught her selling pot, mescaline, and LSD, and placed her in an adolescent therapeutic community--quite engrossingly described here--where, after two years, she has made a good recovery. Blumenthal wants to have it two ways--a cop story and a family drama--and succeeds admirably.