Do not predicate a question based on information submitted earlier by the subject
In many investigations, the subject will have previously offered information, either in writing or verbally. This type of information may be the subject's earlier stated alibi, an earlier statement of events or simply a stated position of denial. It is a prime mistake for the investigator to refer to the subject's earlier statement when asking a question as the following examples illustrate:
"I see you are presently unemployed (in reference to an employment application), why did you leave your last employer?"
"In your deposition you stated that you were never alone with Ms. Kelly, is that correct?"
"The other night you told the officer that you arrived home around 8:00 that evening. Where were you before 8:00?"
By incorporating a subject's earlier statement within the question the investigator, in essence, is accepting the truthfulness of that statement. A subject who is told that he earlier testified that he was never alone with the victim of the crime is unlikely to state, "Actually I lied during that deposition. In truth I was alone with her for about 15 minutes." In addition, by predicating a question based on information earlier submitted by a subject reminds that person of what their earlier response was and this decreases the likelihood of detecting inconsistencies between the two accounts. This concept naturally leads to the next guideline.
Do not reveal incriminating evidence until first asking the subject about it
It is an axiom of interviewing that a subject who lies about small things is probably lying about the issue under investigation. On the other hand, a person innocent of a particular crime is inclined to tell the truth about past acts for the simple reason that they came prepared to tell the truth during the interview. Consider a rape suspect who is known to have been questioned before about a rape similar to the one being investigated. It would be improper to ask this suspect, "I know you were a suspect in a previous rape allegation, what happened there?" A much more productive question to ask would be, "Have you ever been questioned concerning an allegation of rape before?" This question allows the truthful subject to acknowledge the earlier investigation and places the deceptive suspect in a dilemma. He must decide whether to reveal that he was previously investigated or lie to the question. Many guilty suspects will deny being questioned about such previous accusations.
Do not suggest a possible answer within the question
Because investigators routinely conduct interviews, they often form an expectation of what a person's answer will be to an interview question. To elicit this answer more efficiently, there is a tendency to provide the expected response within the question. When the expected answer is less than the truth, however, the investigator has made it very easy for the deceptive subject to lie to him as the following examples illustrate:
Q: "After you left work last night, did you drive straight home?"
A: "That's right."
Q: "Did you return to work at all that night, or did you just stay in your apartment?"
A: "I stayed in my apartment."
Q: "So you heard your neighbors arguing last night. What were they arguing about, money problems or something?"
A: "Yeah, it was something like that."
Had the investigator's question not suggested a response, much more meaningful and accurate information may have been learned:
Q: " Where did you go after you left work last night?"
A: "Well, I stopped off to talk to a friend and eventually drove home."
Q: "Did you return to work at all that night?"
A: "As I recall, I spent most the night in my apartment."
Q: "So you heard your neighbors arguing last night. What were they arguing about?"
A: "It's pretty common knowledge that they had marital problems. From what I heard it sounded like she was going to leave him."
Do not tag a question
Tagging a question refers to adding unnecessary information to an already asked question. Often the investigator asks the initial question and senses that the suspect appears uncomfortable so, to relieve the suspect's discomfort, the investigator continues talking. One reason for this guideline is that it makes the investigator's question longer, thus allowing the deceptive suspect more time to formulate a more credible response. The primary difficulty encountered when tagging a question is that by doing so the question almost always becomes more specific and may invite deception. The following tagged question allows a suspect guilty of committing a burglary shortly after leaving school to answer the question without lying:
Q: "Where did you go after leaving school that day? Did you meet up with friends or maybe go out for a soda or something?"
A: "No. I didn't get together with any friends." (The suspect did not meet up with friends or go for a soda, he broke into a home)
Had this question been limited to, "Where did you go after leaving school that day?" The suspect is forced to lie outright or engage in some form of evasion which may elicit helpful behavior symptoms, e.g., "Where did I go? Well, I pretty much went straight home." The following are examples of improperly tagged questions followed by the properly formulated question:
IMPROPER: "Is there anyone you suspect of doing this. Now I realize that you may not know people very well because you're new but maybe you've heard a rumor or saw something unusual."
PROPER: "Is there anyone you suspect of doing this?"
IMPROPER: "Has anything like this ever happened to you before. Now, I'm not suggesting that you hang around with people who do this sort of thing but sometimes people get in circumstances out of their control and they might get questioned about doing something or maybe even they were just questioned as a witness to what someone else did. Has that happened?"
PROPER: "Has anything like this ever happened to you before?"
Avoid opinion questions when seeking specific information
Opinion and judgment questions form the basis for many of the behavior provoking questions that make up the Behavior Analysis Interview and are of immense value during an interview. However, when seeking specific information about a person's behavior (what was done, what he said, what was heard, what was seen) an opinion question is unlikely to elicit meaningful information. Opinions or judgements are not fixed in time and, therefore, can be modified to fit a person's needs at any given point in time. On the other hand, behaviors are fixed in time and cannot be altered or changed through psychological manipulation -- either a person did or said something or he did not.
Consider a homicide investigation where a husband is being interviewed concerning the shooting death of his wife, Gloria. To explore possible motives for this crime an investigator may ask the husband, "How did you get along with Gloria?" The guilty suspect can easily respond to this opinion question by saying, "We had a really great relationship, I can't believe she's gone." In the husband's mind 90% of the relationship was great and he really is having a hard time believing that he lost his temper and shot her. Proper questions to ask to explore the husband's motivations should center around behavior as the following illustrate:
"The night your wife was killed did you have an argument with her?"
"The night your wife was killed did either of you raise your voice toward each other?"
"The night your wife was killed did you discuss a topic of disagreement?"
"The night your wife was killed did you learn something that upset you?"
The husband may, of course, lie to these questions but because they specifically address behaviors, these questions are likely to elicit verbal and nonverbal symptoms of deception.
A classic example of improper use of opinion questions is illustrated in the screening process of employees considered for sensitive positions. Because of my position, I have been interviewed on a number of occasions concerning past students or acquaintances. During these security-screening interviews I was asked questions similar to the following:
"Is this person considered trustworthy?"
"Does this person have a problem with alcohol?"
"Is this person addicted to any illegal drugs?"
"Has this person done anything to bring into question their loyalty to the United States?"
"Does this person pose a threat to the national security of the United States?"
It would require an extremely forthright person (or perhaps one with a vengeance motive) to volunteer adverse information when asked these opinion questions.
Avoid memory qualifiers
Memory qualifiers can be a good symptom of deception when the interviewer's question is direct and does not require long-term recall. Consider the following exchange:
Q: "Did your niece ever touch your bare penis?"
A: "As far as I recall she hasn't."
However, when asking a sensitive question it is common to include memory qualifiers within the question to ease the stigma of the statement. An everyday example is when answering the phone and it is clear that the person on the other end has dialed the wrong number. We don't say to the caller "You've dialed the wrong number," rather, we say something like, "I believe you may have the wrong number." In retrospect, this is a silly statement to make since there is absolutely no doubt that the other person called the wrong number and yet we incorporate qualifying words (I believe, may) to allow the caller to feel better about his mistake. Similarly, during an interview, when a memory qualifier is included in the investigator's question, the deceptive subject experiences less anxiety during their response. Examples include:
Q: "Do you recall if you signed your name on this check?"
A: "No I don't."
Q: "Do you remember having an argument at all with your wife last night?"
A: "Not at all."
Had the memory qualifier been omitted from these questions, the subject may reveal significant behavior in his response:
Q: "Did you sign your name on this check?"
A: "I don't remember doing that."
Q: "Did you have an argument at all with your wife last night?"
A: "I wouldn't really call it an argument, it was more of a disagreement."
Do Not ask Negative questions
The final guideline appears very obvious and yet is frequently violated. A negative question is one that expects agreement to a premise within the question. The following examples each represent negative questions:
Q: "You don't know who did this, do you?"
Q: "No one ever gave you the combination to the safe, did they?"
Q: "You didn't leave your apartment for any reason, did you?"
The phraseology of each of these questions most certainly will elicit agreement from the subject, regardless of the truthfulness of that agreement. Many times negative questions are asked as an improper follow-up question to an evasive response, as illustrated in the following dialogue:
Q: "Were you ever inside her apartment?"
A: "I hardly knew her so I've never had a reason to be in her apartment."
Q: "So you've never been inside her apartment?"
A: "That's right."
The proper follow-up question to ask in the above interview would have been, "I understand that you hardly knew her but have you ever been inside her apartment?"
An investigator may be very skilled at covering all the relevant areas with a subject during an interview. Yet, if these areas are addressed with improperly formulated question the investigator may fail to elicit meaningful information. Furthermore, improperly phrased questions may not stimulate behavior symptoms indicative of deception. The end result is that a deceptive subject may escape detection.
Formulating proper interview questions is an acquired skill that takes practice. To improve this skill it is beneficial to electronically record interviews. This allows the investigator to go back and identify mistakes in question formulation. This evaluation can also be done by a third party who is either present during the interview or listening in an adjoining observation room.