Because the effectiveness of any police agency is dependent upon its reputation for integrity within the community, internal affairs units for investigating serious violations of the law by police officers should be established by all police departments. An internal affairs unit should act with integrity, be responsive to complaints from both inside and outside the agency, and keep an accurate record of its activities. Citizens should not be discouraged from presenting complaints, and each complaint should be recorded and its progress monitored. Precautions should be taken to segregate internal investigation files from personnel records to ensure confidentiality and to avoid unjustly affecting police officers' evaluation and promotion opportunities. During an investigation of police misconduct, the suspected officer is entitled to a hearing. The complaining citizen is entitled to present his complaint of misconduct in person, by letter, or by telephone. Complaints may be anonymous. The police department is entitled to use its own internal investigation procedures in determining the culpability of its officers for misconduct. However, the community has a right to expect that the police department will expeditiously and legally resolve citizen complaints. The investigative tools of questioning, use of the polygraph, administering of physical tests for obtaining evidence, search and seizure, lineups, and entrapment procedures should be applied in a manner consistent with local legislation and an officer's constitutional rights.