In Yesterday, Today and Tomorrow, the 1963 film starring Sophia Loren, postwar Naples was awash with contraband cigarettes. Today the Italian city is afflicted with a more serious criminal commodity: heroin. Addiction among the young is so widespread that parents have begun to hire private eyes to keep a drug watch on their children.
Mauro Centracchio, the best known of the investigators, has been retained by nearly 100 anxious parents, who pay him $2,900 each to have their offspring shadowed and photographed. Pictures of children buying drugs or shooting up are quickly dispatched to the parents. The former carabiniere calls his...