Interrogation of suspects may be undertaken using oppressive and underhand tactics to obtain information and convictions. The situation is aggravated by arrogance in assuming possession of interviewing skills and by pressures to ensure convictions, irrespective of the quality of the investigation. Police may for example: ask questions on matters other than the alleged offence; misrepresent the law; assert their knowledge pr belief without factual basis; produce or refer to evidence which the solicitor and suspect have not been told about; misrepresent information; or exert pressure on the suspect by questioning in a burdensome manner, behaving abusively or attempting to influence decisions.
Courts in some countries, notably the UK and the USA, rule confessions inadmissible evidence, even when interrogations have been taped. There are many examples of officers losing their tempers during interrogation, shouting at suspects, and using verbal abuse (including graphic advice concerning what should be done with them). Physical abuse during interrogation is common in many countries. It is reported that 70% of women detained in Pakistan had been subject sexual or physical assault although no officer had ever been criminally punished as a consequence.