The field interview/interrogation process provide key pieces to the criminal puzzle. When either is done ineffectively or illegally, it can ruin a good case. There are both differences and similarities between the field interview and the formal interrogation.However, effective tactics and techniques used in one can also be effective in the other.The field interview is the officers first contact. It may involve victims or witnesses, and, in some cases, knowingly or unknowingly with the incident perpetrator. It is generally conducted on a conversational, non-accusatory level with the first responder doing only about 20% of the talking. He/she is gathering basic information; the who, what, when, where and why of an incident.
The formal interrogation is accusatory and is normally carried out when there is a strong belief that the person interviewed may have been involved in a crime. It is an interview conducted with stress, in which the subject is denied the opportunity to deny, and in which the interrogator does most of the talking, leading the subject toward a confession. This program is designed to make law enforcement officers more effective in extracting information in either circumstance.