From a list of reasons cited by the Drug Enforcement Administration for suspecting travelers of transporting drugs. Originally compiled by a judge, the list appears in Unwarranted: Policing Without Permission, by Barry Friedman. The book will be published next month by Farrar, Straus and Giroux.

Arrived at night

Arrived early in the morning

Walked rapidly through the airport

Walked aimlessly through the airport

Used a one-way ticket

Used a round-trip ticket

Carried brand-new luggage

Carried a small gym bag

Traveled alone

Traveled with a companion

Acted too nervous

Acted too calm

First to deplane

Last to deplane

Deplaned in the…