Interrogating Suspects in a Private Investigation
Private Investigation Education: Interrogation
Careful mental preparation is absolutely and unequivocally required before interrogating. Mental preparation involves:• Developing a full knowledge of case facts by, for example, studying the statements of witnesses, notes, sketches, photographs, documents, and forensic findings.• Mentally reconstructing the commission of the incident. Anticipating denials.• Preparing a list of logically ordered topics to be covered during the interrogation.• Preparing a list of questions for each topic.
The general rule is to question witnesses first and the suspect last. But you can bend the rule when you think that early questioning will keep the suspect from fabricating an alibi or synchronizing a story with accomplices.
The timing of an interrogation should rely on advantages to be gained. Ask yourself “If I interrogate now, what advantages can I gain?” Potential advantages are discerned from weighing many factors, such as the evidence at hand, your readiness, and the vulnerability of the suspect. Interrogating is like waging a war, and winning the war is often a matter of knowing when to attack.
Evaluate the Suspect
Generally speaking, physiological changes that occur in a suspect’s body are stronger with persons of high intelligence. This does not mean that the indicators of deception are always more visible; the intelligent suspect may possess a well-developed capacity to conceal inner tension. A suspect with low intelligence may not understand he/she/ is under attack or may not appreciate the full extent of the danger.
A suspect may be emotionally unstable as the result of something entirely separate from the matter under investigation, and it is always difficult to interpret the behavioral signals of an emotionally unstable person. The non-verbal forms of communication exhibited by an unstable person are exactly opposite of a stable person.
Some behavioral signals have cultural or ethnic roots. A gesture might appear to be a deceptive signal when in fact it was a typical, normal expression used by the individual during his interactions with other persons of the same culture or ethnic background.
When a suspect is under the influence of drugs or alcohol, there may be a delay in the response time between stimulus (question) and reaction (deceptive signal). If you believe a suspect is under the influence, terminate the interrogation.
Arrange the Environment
Furniture and seating arrangements should be such as to place the interrogator in a comfortable, psychologically dominant position in relation to the suspect. The physical environment should be interrogator-friendly and provide privacy. It should have clerical assistance, people nearby to serve as observers, and audio/video equipment. An interrogation room is typically plain, but comfortably furnished, and devoid of pictures or items that can distract attention. A room used only for interrogating often will have a built-in two-way mirror. The room must be neither so hot nor so cold as to permit later contentions that information was extracted through physical discomfort. Furniture should consist of three comfortable chairs and a table large enough to write on but not large enough for the suspect to use the table as a psychological barrier. Items that will be needed, such as pens, paper, and forms, should be in place prior to beginning. If the room is equipped with a telephone, it should be disconnected or removed for the purpose of eliminating interruption. Any item in the room that could be used as a weapon must be removed.
Conduct the Interrogation
Interrogation can be time-consuming but this is hardly a reason for hurrying through. A time limit should not be set but neither should the length of the interrogation suggest in any way that the suspect had been denied basic human needs such as rest, food, drink, and toilet use.
The suspect should be seated at the side of a table where you can fully observe body language. If there is a window in the interrogation room, chairs should be arranged so that window light falls on the face of the suspect rather than your face. Chair arrangement should also preclude the suspect from being able to gaze out a window.
Control of the interrogation is in great measure dependent on the initial impression made by you. Because first impressions are important, your appearance must be such that an aura of competence and self-confidence is projected. Your opening remarks should be appropriate in terms of how you evaluate the suspect. For example, a suspect who considers himself or herself superior to you may be addressed by his last name, instructed to sit, instructed not to smoke, and manipulated in ways that quickly establish you as the person in charge.
The degree of success or failure at eliciting information is linked to your ability to estimate the probable guilt of the person to be interrogated. Is the individual a possible suspect or a darn …