In terms of police duties, which action signifies the enforcement of laws?

Issuing a citation for a traffic violation clearly signifies the enforcement of laws. This action is a direct application of legal authority, where law enforcement officials are taking steps to uphold traffic regulations as outlined by law. When an officer issues a citation, they are not only identifying a violation but also enforcing compliance by requiring the individual to adhere to established laws, which serves to maintain order and promote public safety on the roads.

The other actions listed do not directly involve the enforcement of laws. Writing reports for past incidents involves documentation and analysis but does not actively enforce current laws. Participating in community events fosters relationships and encourages community engagement, while conducting research on crime trends helps in understanding and combating crime but does not involve immediate law enforcement actions. Thus, issuing citations is the clear example of law enforcement in practice.