What is a common tool used by HSI agents in investigations?

Surveillance equipment is a crucial tool utilized by HSI agents in investigations, as it allows for the collection of evidence and monitoring of criminal activities without the need for direct confrontation. This equipment, which can include cameras, audio recorders, and tracking devices, enables agents to gather intelligence on suspects and their operations, often leading to successful interventions and arrests. The use of surveillance is vital in maintaining the integrity of an investigation, ensuring that evidence is collected lawfully and effectively.

In contrast, other options such as advanced computer games, while possibly useful in training scenarios, do not serve as direct tools in field investigations. Physical strength assessments pertain more to the recruitment process rather than ongoing investigative activities, and public relations materials, although significant for community engagement, do not provide direct investigative support. Therefore, the choice of surveillance equipment aligns directly with the core functions of HSI operations.