The police interview is one of the most important investigative tools that law enforcement has close at hand. The present work comprising three empirical studies and focusing on the police interviews in very serious crimes of violence and sexual offences. This research showed that police interviews marked by dominance were mainly associated with a higher proportion of suspects' denials whereas an approach marked by humanity was significantly associated with admissions. Crime victims' experience of an interviewing style marked by dominance was significantly associated with the victims' omissions of information whereas a humanitarian interviewing style was significantly related to victims providing all information from painful events. Special squad police officers' attitudes towards interviewing suspects and crime victims may be affected by traumatic experiences in duty and may automatically generate dominant attitudes. The police interview is multi-faceted and thoroughly related to cognitive as well as social psychology. The reader of this book will realize that legal procedures not only have juridical effects, but to the highest degree, also psychological effects.