Some interviews are free-flowing and spontaneous. Often, these interviews are conducted in an uncontrolled environment such as a street corner, an employee's office or over the telephone. Because the person being interviewed in these situations is generally telling the truth, the investigator does not have to carefully structure an interview strategy. However, when interviewing a person who is motivated to lie to the investigator, the interview should not be haphazard or spontaneous. It should be carefully planned out and structured to achieve the desired goals.
While some suspects make incriminating admissions or even confess during an interview, obtaining a confession should not be the primary goal of an interview. Rather, an interview is conducted to elicit information. This information can be divided into two broad areas. The first could be termed investigative information such as the person's opportunity, access, motives and propensity to commit the crime. Second, the investigator should ask questions specifically designed to elicit the suspect's guilt or innocence. Some of the characteristics of a formal interview include:
1. The investigator's demeanor is non-accusatory and non-judgmental
2. The interview is conducted in a controlled environment
3. The primary interview questions are prepared ahead of time
The principal benefit of preparing an interview strategy is to make certain that all of the necessary questions are asked during the interview. During a formal interview often the investigator only has one opportunity to ask the suspect questions, and careful thought should go into covering all the important areas. Second, by preparing an interview strategy, the investigator does not have to spend time thinking about what question to ask next. Rather, he can focus his efforts on asking necessary follow-up questions and observing the suspect's verbal and nonverbal behavior. Finally, the structure of the interview allows the investigator to come across as well prepared, proficient and a difficult person to lie to.
While the questions asked during any interview will be unique to the particular suspect and issue under investigation, the following guidelines can be used to help organize those questions and also provide a logical flow to the interview. As will be presented shortly, we suggest an opening and closing strategy with six specific blocks of questions occurring between them. The specific order of these blocks of questions is not critical. However, we do recommend that all similar questions (e.g., opportunity/access questions) be covered in their entirety during a particular block of the interview. This will allow the suspect to focus attention on one particular area at a time and not become confused or give inconsistent answers because of major shifts in questions from one topical area to another.
Starting the Interview
At the outset of the interview the investigator should provide the suspect with an overview of the interview coupled with a statement emphasizing the importance of being completely truthful. The following is a possible opening statement in an employee theft investigation:
"Mark, let me explain the interview process. I'm going to start off this afternoon by getting some background information from you and then we will talk in detail about the deposit shortages. It is important for you to understand my role in this whole investigation. I don't get paid to judge people as being good or bad and I don't have any authority over what happens to the people I talk to. My job is to simply collect and analyze evidence and a big part of that involves talking to people. During our interview this afternoon I want to make certain you understand each of my questions so if there is anything you do not understand, please ask me to clarify it. It is also important for you to be completely truthful with me before you leave today. Does that all sound agreeable? Alright. I'm going to start off by having you spell your last name for me."
This introduction establishes the non-accusatory tone of the interview, and also the non-judgmental position of the investigator. The emphasis on being truthful, as opposed to a threatening statement (such as, "If you lie to me today I will prove that and you will be sorry!") will work to the investigator's advantage later if it becomes necessary to interrogate the suspect.
The first couple minutes of the interview should consist of non-threatening background questions such as the spelling of the suspect's name, his address, marital status, job duties, etc. These questions allow the investigator to establish the suspect's behavioral norms within the areas of eye contact, communication style and general nervous tension. In addition, these initial questions allow the investigator to establish a rapport with the suspect.
The issue under investigation may be introduced by asking the suspect, "Tell me everything you know about (the issue under investigation)." Regardless of the suspect's answer to that question, it is very important for the investigator to first precisely define the issue under investigation and then ask the suspect whether or not he committed the crime. The following is an example of this in a date rape case:
"Jerry, Linda Jones has reported that last Saturday evening you undressed her and forced her to have sexual intercourse with you by striking her with your hand. If you did do that our investigation will clearly indicate that. On the other hand, if this did not happen it will show that as well. Before we go any further, let me ask, did you force Linda to have sex with you last Saturday evening?"
The reason it is important to precisely identify the issue under investigation is so that the suspect knows whether or not he is innocent or guilty of that issue which, in turn, will affect the validity of his behavior during the interview. Consider that Linda Jones had consensual intercourse with the suspect but that the two of them used cocaine that night. If the investigator is vague in his questions such as, "Jerry, did you do something wrong with Linda last Saturday?" the suspect may exhibit very misleading behavior during the interview.
One reason it is important to ask a suspect, early during an interview, if he committed the crime is because innocent suspects are anxious to let the investigator know that they did not commit the crime. However, if the investigator does not allow the innocent suspect to tell the truth, this may result in increased anxiety which could be interpreted as deceptive behavior. The second reason to directly ask a suspect if he or she is guilty of the crime, is to heighten the suspect's level of motivation during the interview. On the other hand, if the investigator skirts around the issue and avoids sensitive areas, the innocent suspect is not motivated to convince the investigator that he did not commit the crime. Similarly, a guilty suspect may not be motivated to conceal the fact that he is lying. When a suspect's level of motivation is low, behavior symptom analysis can be very unreliable.
Developing Information Concerning investigative leads, Opportunity and Access
After asking the suspect if he committing the crime it is often appropriate to ask some preliminary questions to address guilty knowledge, complicity or general theories of the crime:
"Do you know for sure who did (commit the crime)?"
"Who do you suspect may have (committed the crime)?"
"Is there anyone you can eliminate as a suspect?"
At this point during the interview the investigator may want to elicit specific investigative information. Examples of possible investigative questions include:
"Tell me everything you did last Saturday night between 8:00 and the time you fell asleep."
"Describe your relationship with Linda Jones."
"What was Linda's mood when she left your apartment on Saturday?"
"Tell me everything about preparing the deposit last Friday afternoon?"
"Did anything unusual happen while you were making up the deposit?"
"Do you have the combination to the safe?"
Developing Attitudinal Information
Truthful and deceptive suspects form very different and predictable attitudes toward the interview as well as the issue under investigation. At some point the investigator will want to ask specific questions to draw out these attitudes. Examples of questions designed to do this include:
"How do you feel being interviewed concerning (issue)?"
"Who would have had the best opportunity to (commit crime) if they wanted to?"
"Do you really think (the crime was committed)?"
"What do you think should happen to the person who (committed issue)?"
Developing Information Concerning Motives and Propensity
One block of interview questions should explore the suspect's motives and propensity. If the crime is financially motivated it would be appropriate to discuss the suspect's current financial status. If the circumstances of the crime appeared to be linked to substance abuse, it would be appropriate to ask the suspect about his use of alcohol and illegal drugs. To evaluation propensity to commit the crime, the following questions may provide insight:
"What is the closest thing to (issue under investigation) that you've ever done?"
"Have you every thought about (committing the crime)?"
"Tell me why you wouldn't (commit crime)?"
"Have you ever been approached by anyone asking you to (commit crime)?"
"Have you ever been questioned before about (issue under investigation)?"
Developing the Suspect's Explanation for any Evidence
If there is physical or testimonial evidence pointing to the suspect's possible involvement in the crime, the investigator may want to bring this up during the interview. On the other hand, if the investigator knows that the suspect will be eventually interrogated, often it is beneficial to wait until the interrogation to bring up actual evidence of the suspect's guilt.
Developing Information About the Suspect's Confidence
During a non-accusatory interview innocent suspects are confident they will be believed whereas guilty suspects are worried about getting away with their crime. The following questions are designed to assess the suspect's confidence during the interview:
"When Linda says you slapped her is she lying?"
"Can you think of any reason why someone would name you as the person they suspect?"
"Once we complete our investigation how will it come out on you?"
"Can you think of any reason why the surveillance video would show you inside the vault last Friday afternoon?"
Concluding the Interview
Once all of the relevant information from the suspect has been elicited, the investigator should step out of the interview room, review his interview notes and other evidence collected in the case and make one of three decisions. The first is that the suspect is telling the truth an can be eliminated from further suspicion. Under this circumstance, the investigator should return to the interview room and say something like the following, "Tom I've covered everything I need to cover with you. Thank you for coming in. If I need to talk to you further I'll let you know." A second possibility is that the investigator decides, based on the suspect's behavior and the evidence, that the suspect is probably guilty of the crime. Under this circumstance, the investigator would return to the interview room and start the interrogation.
In some situations, following the initial interview the investigator may not be able to make a determination of the suspect's probable guilt or innocence. In other cases, even though the investigator is quite certain of the suspect's guilt, he may not want to interrogate the suspect at that time. Under these circumstances the investigator would return to the interview room and tell the suspect something similar to the following, "Bill, thank you for coming in today. We are in the process of talking to other people and waiting to get results back on some forensic evidence and it may be necessary for me to talk to you again. You'd be willing to come back and talk to me, wouldn't you?"
In conclusion, an investigator often has only one opportunity to conduct a formal interview of a suspect. To maximize the amount and quality of information learned during the interview, a specific structure should be used. The issue under investigation should be clearly defined and a series of prepared questions should be asked to develop investigative information and behavior symptoms of truth or deception.