Private Investigation: The Serious Incident
Every once in a while a private investigator will be interviewing a witness concerning a serious incident such as a wrongful death, aggravated assault or rape. The witness says or does something that causes the PI, who is most likely a criminal defense investigator, to believe the witness is not a witness at all, but the guilty party. The PI switches to the interrogation mode, but what is that mode? Interrogation experts say that an interrogation should consist of three stages: (1) establish rapport, (2) let the suspect tell the story and (3) challenge the story.
In the rapport stage the interrogator engages the suspect in innocent conversation such as asking questions about the suspect's hobbies, interests and so forth. The objectives are to assess the suspect's intelligence and attitude; get the suspect use to talking; and establish a relationship in which the interrogator is the dominant person.
In the second stage the suspect is encouraged to tell the story. Interruptions should be as infrequent as possible and non-threatening such as to say "Go on" or "What happened then?" The interrogator looks for obvious lies, such as comments that contradict what is already known, and other indicators that the suspect is untruthful or omitting facts. The interrogator wants to obtain as much information as possible so that there will be plenty to discuss in the third stage.
In the third stage the interrogator points out the discrepancies and gauges the suspect's verbal and body language responses. These are called Deception Cues and can be (1) phrases like "Honest to God" and "This is the truth", (2) avoiding the interrogator's eyes, (3) twitching, (4) bouncing knees, (5) drumming fingers, (6) licking the lips, (7) arms across the chest; (8) picking imaginary lint from clothing, (9) showing no emotion such as not inquiring about or expressing concern as to the victim's condition and (10).giving answers that are protective and show self-concern.
Another deception cue is called Cognitive Dissonance. The suspect's mind is furiously concocting an answer but his mouth can't keep up. Words are garbled and out of order.
The suspect may offer an explanation before a question is asked. For example, "By the way, that blood spot on the seat of my car was caused by her when she sneezed and had a nosebleed." The blood spot may not have been detected by the police, a circumstance that would weaken the prosecution's case and strengthen the defense. Another example is, "The stairs are very steep and that is why she fell down them." If the private investigator has already been to the scene and taken photographs, they might reveal that the stairs are not steep at all. Showing the photos to the suspect is a way to point out an obvious lie.
If the incident involved physical violence, the interrogator will want to look for cuts, scratches and bruises inflicted by the victim.
When the interrogator reaches a point where further questions will not be helpful he or she moves to a method called Theme Development. In this method the interrogator suggests a scenario in which the suspect had little choice except to commit the offense. The theme is a story that portrays the suspect as a decent person that was confronted with unavoidable circumstance requiring a course of action. The interrogator might suggest that the victim was at fault, that the offense is not all that serious, that the average person would do the same and that people understand and be sympathetic. Theme Development offers the suspect an opportunity to make excuses that are self-exculpatory -- yet incriminating.
Care must be taken not to elicit a false confession through extended interrogation, verbal abuse, inappropriate touching or misuse of the Two-Path technique by describing harsh punishment that is inevitable when the suspect does not confess as opposed to describing positive help and understanding that results from an admission. (Note: Many people believe that false confessions are rare but the advent of DNA testing shows that not to be the case.) Care must be taken to prevent the suspect from later claiming that he or she was denied use of the bathroom, not allowed to rest and not given water or food.
It can be helpful to have another private investigator present to take notes and serve as a witness. A video recording is extremely important because it can be used at a later time to verify and discover new Deception Cues, show that the interrogation was not excessively coercive (an interrogation is coercive to some extent always) and create pictorial evidence for presentation at trial.