Use of force by law enforcement is a controversial issue in countries across the globe. There is no universal standard that defines its justification absolutely; as a
consequence, each case is analyzed individually based on known variables, which creates legal uncertainty for both the officers who have to use force and the citizens against whom force is used.

The concern about this issue is not new—since the mid-20th century, several rules and regulations related to the use of force, derived fundamentally from the Universal Declaration of Human Rights, have been developed, an evolution that can be seen as the turning point for defining the modern police profession. The fruit of these rules is the promulgation of international legal instruments that define the impassable lines on the use of force by law enforcement—reiterating in all of them the prohibition of torture and cruel, degrading, and inhuman treatment—as well as stating the guiding principles: proportionality, congruence, and necessity. With these overarching principles and international instruments as baselines, each agency establishes regulations, according to the agency’s needs and experiences, at the national, regional, and local levels. Recently, 11 law enforcement groups and as­­­sociations, including the IACP, published The National Consensus Policy on Use of Force in an effort to provide law enforcement officers with uniform guidelines for the use of less-lethal and deadly force