A vowel is that which without impact of tongue or lip has an audible sound. The Poetics of Aristotle by Aristotle View in context. J is a consonant in English, but some nations use it as a vowel --. The Devil's Dictionary by Bierce, Ambrose View in context.
More commonly, these positions can be grouped under the title of law enforcement officers. A Peace Officer is any person who works in the public-sector and whose responsibility is to uphold the peace. Types of Peace Officers may include customs officers, police officers, sheriffs, probation officers and the like. It is the daily duty of these professionals to uphold the law and maintain the peace in the jurisdiction in which they work.
Contract security officers may enforce certain laws and administrative regulations, which may include detainment or apprehension authority, but not arresting. Peace officers may also be able to perform all duties that a law enforcement officer is tasked with, but may or may not be armed with a weapon.