Recommended Practice

Identifying Suspicious Behavior in Mass Transit


This Recommended Practice establishes minimum guidelines for identifying suspicious behavior in mass transit.

Document History
Document Number Version Publication Date Publication Related Information
APTA SS-SRM-RP-009-09 Rev. 2 07/29/2022 Published Current
APTA SS-SRM-RP-009-09 Rev. 1 09/25/2020 Published Superseded
APTA SS-SRM-RP-009-09 10/15/2009 Published Superseded


human trafficking, identifying, security, suspicious, suspicious behavior, terrorism, transit


Transit systems by nature are open and easily accessible by the public—and thereby are easily accessible by terrorists and criminals. It is impractical for transit agencies to use the screening practices used in airports. Terrorists and criminals could be of any race, color, gender, religion, ethnicity, national origin or age. Selective screening of passengers based only on these characteristics is profiling and is unconstitutional and unlawful. An acceptable method of securing transit agencies is to monitor and identify suspicious behavior. This recommended practice provides transit staff guidance and procedural guidelines for identifying suspicious behavior and potential criminal activity. It includes criteria for identifying potential crimes in progress, as well as basic behavioral characteristics of possible criminals and/or terrorists.

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