"Every person who, under color of any statute, ordinance, regulation, custom, or usage, of any State or Territory or the District of Columbia, subjects, or causes to be subjected, any citizen of the United States or other person within the jurisdiction thereof to the deprivation of any rights, privileges, or immunities secured by the Constitution and laws, shall be liable to the party injured in an action at law, suit in equity, or other proper proceeding for redress, except that in any action brought against a judicial officer for an act or omission taken in such officer’s judicial capacity, injunctive relief shall not be granted unless a declaratory decree was violated or declaratory relief was unavailable. For the purposes of this section, any Act of Congress applicable exclusively to the District of Columbia shall be considered to be a statute of the District of Columbia."

The Bureau of Justice Statistics(BJS) in Data Collection on Police Use of Force, states that "…the legal test of excessive force…is whether the police officer reasonably believed that such force was necessary to accomplish a legitimate police purpose…" However, there are no universally accepted definitions of "reasonable" and "necessary" because the terms are subjective. A court in one jurisdiction may define "reasonable" or "necessary" differently than a court in a second jurisdiction. More to the point is an understanding of the "improper" use of force, which can be divided into two categories: "unnecessary" and "excessive." The unnecessary use of force would be the application of force where there is no justification for its use, while an excessive use of force would be the application of more force than required where use of force is necessary.