ensure that the investigation leads to a particular result, but the authorities must have taken the reasonable steps available to them to secure the evidence concerning the incident. Thoroughness The investigation should be comprehensive in scope and address all of the relevant background circumstances, including any racist or other discriminatory motivation. It should be capable of identifying any systematic failures that led to the violation. This requires the taking of all reasonable steps to secure relevant evidence, such as identifying and interviewing the alleged victims, suspects and eyewitnesses; examination of the scene of the alleged violation for material evidence; and the gathering of forensic and medical evidence by competent specialists. The evidence should be assessed in a thorough, consistent and objective manner. Impartiality and independence Persons responsible for carrying out the investigation must be impartial and independent from those implicated in the events. This requires that the authorities who are implicated in the events can neither lead the taking of evidence nor the preliminary investigation; in particular, the investigators cannot be part of the same unit as the officials who are the subject of the investigation. Promptness The investigation must be commenced with sufficient promptness in order to obtain the best possible amount and quality of evidence available. While there may be obstacles or difficulties which prevent progress in an investigation in a particular situation, a prompt response by the authorities may generally be regarded as essential in maintaining public confidence in the maintenance of the rule of law and in preventing any appearance of collusion in or tolerance of unlawful acts. The investigation must be completed within a reasonable time and, in all cases, be conducted with all necessary diligence. Public scrutiny There should be a sufficient element of public scrutiny of the investigation or its results to secure accountability, to maintain public confidence in the authorities’ adherence to the rule of law and to prevent any appearance of collusion in or tolerance of unlawful acts. Public scrutiny should not endanger the aims of the investigation and the fundamental rights of the parties. Appendices ► Page 125