Law enforcement agencies are also concerned with the protection of certain public facilities and infrastructure; providing initial response to emergencies and other threats to public safety; the protection of public officers; the operation of some detention facilities, and the maintenance of public order.

There are certain minimum standard criteria required to be qualified for police training. In the United States, a typical criterion dictates that applicant must:

* Be a United States citizen
* Be in good mental, medical, and physical condition
* Clean criminal record
* Have a valid driver’s license
* Be of high moral character
* Not have a history of mental illness or domestic violence

Applicant needs to undergo repeated medical examinations, interviews, written tests, drug testing, and police oral board interviews to name a few. Recruiting is competitive and failure to meet some minimum criteria automatically disqualifies the candidate. Out of all the examinations, the most subjective one is the police oral board interview and often disqualifies the biggest portion of qualified candidates.