Which of the following is part of a security guard's responsibilities?

Monitoring for suspicious behavior is a fundamental responsibility of a security guard. This task involves observing the environment and the actions of individuals to identify any unusual or potentially harmful activities. By being vigilant and attentive, security guards play a critical role in preventing incidents before they escalate. Their training emphasizes recognizing patterns of behavior that may indicate a threat, which can allow for timely intervention or reporting to law enforcement if necessary.

The other responsibilities listed, such as catching criminals on the run, investigating crimes alone, and engaging in high-speed pursuits, typically fall outside the scope of a security guard's duties and could be dangerous or inappropriate actions for someone in that role. Security guards are primarily tasked with maintaining a safe environment, deterring crime, and reporting incidents, rather than directly engaging with criminals or conducting investigations independently.