The aim of this work is to discuss and present a history of the formation of Public Security in Presidente Prudente, focussing on the creation, installation and trajectory of one of its institutions, today the Military Police of the State of São Paulo, which over time has had various names. To draw some conclusions and even infer some behaviours, daring to foresee projections about its future role, at the service of a society in a permanent and accelerated process of transition.The purpose of this unpretentious reflection is to briefly analyse this evolution, its determining causes and, in particular, the historical and cultural background into which the Force’s institutional personality was moulded. Understanding the institutional performance of the São Paulo State Military Police, its values, beliefs and representations of reality, its norms, its internal culture and the individual conduct of some members, as members of the Institution, evaluating its relations with public authorities and civil society in general, necessarily implies knowing its historical process.