A sworn officer is so called because he or she

has taken an oath of service

can swear on the job when dealing with confrontational individuals

can never leave the police service

vowed to uphold the provisions of the Constitution

Answer: has taken an oath of service

Explanation: Sworn law enforcement officers are those who have taken an oath to support the Constitution of the United States, their state, and the laws of their agency's jurisdiction. Sworn officers also have the responsibility to ensure the safety and quality of life of the communities they serve.