According to Kautilya the suppression of crimes and the maintenance of law and order were the foremost duty of the king. He has called these anti-social elements as Kantakas or thorns in the body politic of the empire.
The weeding out of these thorns, Kantakasodhana, i.e. the suppression of criminals and other anti-social elements, was a basic function of the state. The Arthasastra devotes the entire Fourth Book to this topic.
The general condition of law and order then prevailing in the country as a whole was very good. Megasthenes has commented that “there was rarity of law suits among Indians. They are not litigious. Witnesses and seals are unnecessary when a man make a depost. Their houses are unguarded”. A general sense of law and order was, however, consistent with, and perhaps maintained by a severe Penal Code.
The Pradesika were the principal police officers, whose duty was to investigate the crimes committed in the region within their jurisdiction. All crimes were properly investigated and a great emphasis was placed on the thoroughness of the investigation in the case of major crimes.