They enter the massage parlors as undercover detectives. They leave as satisfied customers. In Spotsylvania County, as part of a campaign by the sheriff's office to root out prostitution in the massage parlor business, detectives have been receiving sexual services from "masseuses." During several visits to Moon Spa on Plank Road last month, detectives allowed women to perform sexual acts on them on four occasions and once left a $350 tip, according to court papers. Spotsylvania Sheriff Howard D. Smith said that the practice is not new and that only unmarried detectives are assigned to such cases. Most prostitutes are...