To identify pieces of mail that might contain controlled substances, postal inspectors rely on a profile based on a readily discernible set of criteria for both the package's condition and its label: (1) heavy taping along the seams; (2) poor preparation for mailing; (3) uneven weight distribution; (4) apparent package reuse; and (5) labels that are handwritten, contain misspellings, originate from a drug-source State, indicate person-to-person not business-to-individual mail, have a return zip code that does not match the accepting post office zip code, a fictitious return address, names of senders or recipients with features in common (John Smith, e.g.) and having no connection to either address. Upon discovery of a suspicious package, postal inspectors notify a police narcotics unit, which assigns a drug-sniffing dog and its handler to inspect the package. The author describes how law enforcement officials have learned from the efforts of postal inspectors and suggests that this knowledge could be applied to detect packages transported by private carriers and parcel services. Endnotes