Alguacil (in Spanish), Aguazil or Guazil (in Portuguese) is a title often to be encountered in stories and plays, derived from the Arabic "وزير (wazir)", meaning "minister", preceded by the article "al".
The Alguacil among the early Spaniards was a judge, and sometimes the governor of a town or fortress, or the master at arms on a vessel. In later times the office was gradually lowered to the rank of an officer of the court, who is trusted with the service of writs and certain police duties, but he is still of higher rank than the mere Corchete or arresting officer. The title has also been given to inspectors of weights and measures in market-places, and similar officials.
There were two types of Aguacils: The Aguaciles Mayores (Chief Justice) and Aguaciles Menores (Justice).
The Aguacils of higher importance were the Aguaciles Mayores. These positions were held by the most prominent families, so they approximated the office of Regidores. (At first they were also in charge of the local prison (jail), but this function was passed very soon to the responsibility of the Alcaide or warden.) Their function was to arrest people provided by the Inquisidor or investigators and the seizure of their property. To do this one had to be accompanied by the recipient, their family members and the Secretary (minister) of Arrests (sheriff). He could seek the support of civil authorities. It also ensured the safety of the detainees (defendants), because they had no communications with others except, of course, those authorized by the investigators. Among the junior officers, the Alguacil Mayor held the largest category with the Secret Notaries. The others functions of an Aguacil Mayor were:
Execute the statements
Stop the criminals.
Public order issues.
Appoint wardens of prisons
Intervene in cases of relevant people.
The Aguaciles Minores generally performed the duties on behalf of the Aguacil Mayor.