However, German political theorist Hannah Arendt noted: "Violence can be justifiable, but it never will be legitimate ... Its justification loses in plausibility the farther its intended end recedes into the future. No one questions the use of violence in self-defence, because the danger is not only clear but also present, and the end justifying the means is immediate". Arendt made a clear distinction between violence and power. Most political theorists regarded violence as an extreme manifestation of power whereas Arendt regarded the two concepts as opposites. In the 20th century in acts of democide governments may have killed more than 260 million of their own people through police brutality, execution, massacre, slave labour camps, and sometimes through intentional famine.Violent acts that are not carried out by the military or police and that are not in self-defense are usually classified as crimes, although not all crimes are violent crimes. Damage to property is classified as violent crime in some jurisdictions but not in all. The Federal Bureau of Investigation (FBI) classifies violence resulting in homicide into criminal homicide and justifiable homicide (e.g. self-defense).The criminal justice approach sees its main task as enforcing laws that proscribe violence and ensuring that "justice is done". The notions of individual blame, responsibility, guilt, and culpability are central to criminal justices approach to violence and one of the criminal justice systems main tasks is to "do justice", i.e.
to ensure that offenders are properly identified, that the degree of their guilt is as accurately ascertained as possible, and that they are punished appropriately. To prevent and respond to violence, the criminal justice approach relies primarily on deterrence, incarceration and the punishment and rehabilitation of perpetrators.The criminal justice approach, beyond justice and punishment, has traditionally emphasized indicated interventions, aimed at those who have already been involved in violence, either as victims or as perpetrators. One of the main reasons offenders are arrested, prosecuted, and convicted is to prevent further crimes—through deterrence (threatening potential offenders with criminal sanctions if they commit crimes), incapacitation (physically preventing offenders from committing further crimes by locking them up) and through rehabilitation (using time spent under state supervision to develop skills or change ones psychological make-up to reduce the likelihood of future offences).In recent decades in many countries in the world, the criminal justice system has taken an increasing interest in preventing violence before it occurs. For instance, much of community and problem-oriented policing aims to reduce crime and violence by altering the conditions that foster it—and not to increase the number of arrests. Indeed, some police leaders have gone so far as to say the police should primarily be a crime prevention agency. Juvenile justice systems—an important component of criminal justice systems—are largely based on the belief in rehabilitation and prevention. In the US, the criminal justice system has, for instance, funded school- and community-based initiatives to reduce childrens access to guns and teach conflict resolution.