Perpetrators of human rights violations, whether civilian or military, become all the more irresponsible if they are not held to account before a court of law. Subversive groups, for their part, may become all the more brazen if their violent acts can be repeatedly unpunished. Impunity can also induce victims of these practices to resort to self-help, acting as judge and executioner at the same time. The interplay among these various factors may exacerbate the level of violence reigning in a country, and thereby further reinforce impunity. Another contributing factor to impunity may be institutional paralysis of civilian justice. Prosecutors and judges may find themselves overburdened and over-threatened, making them slow to respond to the need for inquiries. Paralysis may also occur through lack of cooperation by the executive branch. Other practices facilitating impunity are the intimidation and assassination of witnesses and the obstruction or intimidation by, military authorities of independent inquiries of human rights violations by failing to provide information or to comply with arrest warrants issued by civilian judges.
There is a tendency in countries which have passed from a totalitarian form of government to democracy to promulgate laws or mechanisms which enable impunity to be granted to agents of the former regime responsible for serious violations of human rights. This is used to help consolidate the stability of the democratic government, but it has generated feelings of defencelessness and insecurity in the most vulnerable, and lack of confidence in judicial and democratic institutions.
State security agencies have used such illegal repressive methods as detention without trial and torture, or misused their powers to carry out intelligence operations and raids in order to arrest and hold people. The identity of attackers may then be deliberately concealed from victims. In extreme cases, the perpetrators' certainty that they would never be identified, much less punished, has meant that they have acted with impunity during working hours, perhaps in uniform, in front of witnesses and in official vehicles, subsequently denying any part in the acts.
The involvement of members of different security agencies in an operation, and the illegal use of civilians in security agencies, may make any criminal or disciplinary investigation difficult. The establishment of self-defence groups, which can or do make use of weapons belonging to the armed forces, may be legalized, thus contributing to the number of crimes committed. By keeping no records of either the operations that lead to arrests or of the names of people who are arrested and held in military and police premises, it is easy to ensure the disappearance of people. Authorities conducting preliminary inquiries into abuses may destroy or tamper with evidence. Military tribunals too often leave violations of human rights unpunished. The refusal of authorities to admit any complaints about acts which violate human rights is a crucial factor ensuring the impunity of any violators. Witnesses or complainants in such cases may be intimidated, be murdered or simply disappear.
In Colombia, for example, it was alleged in 1993 that a culture of impunity among officials had been fostered by the repeated suspension of constitutional rights. The system of military tribunals gave their armed forces the right to judge their own crimes. Reforms are often window dressing and fail to weed out and punish guilty people in authority. Constitutional devices are also used to stifle legitimate political opposition.
Impunity is a huge problem in Brazil because of the immense power of the local landlords. They possess extensive areas remaining uselessly uncultivated. They spare no means to prevent landless peasants and other democratic forces from carrying out land reforms for the benefit of the indigent part of the population. They have a strong impact on the local courts, police and military. So they have virtually free hands to get rid of rural workers and others who are struggling for a just distribution of the land and a fair judicial system with guarantees of the public security of the citizens. The fee for having a murder committed by a corruptible policeman is about $1,000.