Executive Summary An independent and effective police complaints system is of fundamental importance for the operation of a democratic and accountable police service. Independent and effective determination of complaints enhances public trust and confidence in the police and ensures that there is no impunity for misconduct or ill-treatment. A complaints system must be capable of dealing appropriately and proportionately with a broad range of allegations against the police in accordance with the seriousness of the complainant’s grievance and the implications for the officer complained against. A police complaints system should be understandable, open and accessible, and have positive regard to and understanding of issues of gender, race, ethnicity, religion, belief, sexual orientation, gender identity, disability and age. It should be efficient and properly resourced, and contribute to the development of a caring culture in the delivery of policing services. The European Court of Human Rights has developed five principles for the effective investigation of complaints against the police that engage Article 2 or 3 of the European Convention on Human Rights: ff Independence: there should not be institutional or hierarchical connections between the investigators and the officer complained against and there should be practical independence; ff Adequacy: the investigation should be capable of gathering evidence to determine whether police behaviour complained of was unlawful and to identify and punish those responsible; ff Promptness: the investigation should be conducted promptly and in an expeditious manner in order to maintain confidence in the rule of law; ff Public scrutiny: procedures and decision-making should be open and transparent in order to ensure accountability; and ff Victim involvement: the complainant should be involved in the complaints process in order to safeguard his or her legitimate interests. These five principles must be adhered to for the investigation of a death or serious injury in police custody or as a consequence of police practice. They also provide a useful framework for determining all complaints. Best practice is served by the operation of an Independent Police Complaints Body working in partnership with the police. Effective investigation of ill-treatment – Guidelines ► Page 82