The suspect was sitting in the interview room of Flemington police station listening to my every word. I had arrested John on suspicion for the commission of 25 burglaries in the Flemington area. Now I had to prove it. Flemington is a heavily populated leafy suburb fifteen minutes west of Melbourne. All I had was the registration number of John’s ageing Holden commodore recorded by an astute neighbour. John’s commodore was parked in Epsom road, Ascot Vale when the neighbour noticed a man in his mid twenties acting “strangely”. John was an active burglar and part time drug dealer with numerous convictions for burglary, theft and deceptions. After parking the unmarked police car behind the commodore my attention was instantly drawn to a dark figure standing by a meticulously maintained single fronted weatherboard cottage. The moment I approached I instantly recognised John’s distinct nose and protruding jaw. John was not exactly surprised to see me. After our initial conversation I arrested John for loitering with intent. An extensive search of nearby houses, gardens, John’s pockets and car revealed little evidence. No tools of trade, no fruits of his labour. John was a professional.

Before interviewing John I gathered previous burglary reports from 30 unsolved cases over the past 6 months. Each burglary had similar patterns: entry always via a forced rear window, similar tool marks on window frames, small items such as jewellery, cash, compact discs and VCR’s stolen. Although there were striking similarities little forensic or scientific evidence was identified at each burglary. I had no fingerprints, no fibre trace evidence, no DNA, no blood, no hair samples, no witnesses, not much of anything really. If only I could locate the jemmy bar used to force the windows maybe a scanning electron microscope could identify tool mark indentations and provide the evidence I needed to charge John. A search warrant executed on John’s house failed to find any corroborative evidence to make that all important nexus between John and each crime scene.

The first question I fired at John was “Well John, did you commit any of these burglaries in Flemington?” His reply? “Nah”. Bad question. That very question implied that I didn’t know myself. If I knew that he committed any of those burglaries then why would I have to ask him if he did? In fact John was assessing what I knew about his involvement. John was using a behavioural analysis technique that, believe it or not, is taught by the FBI. Luckily he didn’t know it.

The purpose of conducting an interview

The interview is often an integral part of an investigation. Although scientific, medical or forensic evidence provides an investigator with valuable clues what do we do if there is no such evidence? I often remember the adage; a confession is a good start to an investigation. Unfortunately very little training is available in the art of conducting effective interviews. Having served in two Police departments and conducted hundreds of criminal interviews throughout my police career I was aware that little time was devoted to this imperative skill. In 1996, whilst training with the Polygraph Unit of the Los Angeles Police Department, I listened to a record of interview conducted by a detective. The suspect was being questioned over a murder that he denied any involvement in. After a skilled interview he was making admissions to the murder and several other criminal matters that detectives had no idea about. The Officer in Charge of the Polygraph Unit said to me “Steve, everyone will tell you what you want to know, the problem is we don’t always ask the right questions”. I often wondered why some people would admit to committing a murder knowing that their confession would win them jail time when others wouldn’t give you their name. The answer is rapport. If someone doesn’t like or trust you they wont take you into their confidence.

The purpose of conducting any type of interview is to elicit information. Sometimes we are unaware if we are interviewing a suspect, witness, co-offender or innocent bystander. Occasionally the witness may become the suspect. By asking the right questions and knowing how to decipher verbal and non-verbal signs of deception we are enhancing our investigation.

By having a structured and methodical approach to interviewing we are able to uncover information that we may not have previously known. Remember that if we are relating a truthful event we have to rely on our memory for detail, content and recall. If we are lying we no longer have to rely on our memory of events but rather what we said previously. For every one lie we tell we have to invent another three to protect ourselves from the first one.

What is behavioural interviewing?

Behavioural interviewing is a technique that uses a structured set of accusatory behaviour provoking questions designed to determine truth or deception. When a person makes a conscious effort to conceal information or wrong doing they often experience internal conflicts that create increased tension and anxiety. The very question they are lying to becomes a very threatening stimulus to them. By identifying when such verbal and non-verbal signs of deception are present we are able to recognise deception with a high level of accuracy. This type of interviewing technique is particularly useful when determining if a person is editing information or fabricating responses.

Examples of behavioural questions

When interviewing someone to ascertain involvement in a particular disciplinary matter or criminal act some of the questions below have proven very effective.

“John, during this investigation we will be interviewing a number of people. Is there any reason you can think of that someone would name you as a suspect?”

The theory here is the truthful suspect will usually reject the suggestion of being named as a suspect outright. Truthful or innocent suspects often are direct and will tell you what they think. Conversely a deceptive suspect may offer weak denials or be evasive.

“John what do you think should happen to the person who stole that $20,000.00 cheque?”

The principle of this question is that the truthful person will usually offer strong punishment such as: “They should be sacked” or “They should go to jail”. These responses are understandable because the innocent person may not be concerned about what happens to the culprit. During one interview when I asked a suspect what he though should happen to the person who stole the money he replied “They should get help. Maybe the guy had a gambling problem or something”. This person later admitted that he gambled the full amount at the casino. His initial response to this question told me why he stole that cheque.

“Sharon, how do you think the results of this investigation will come out on you?”

In response to this question the truthful person will usually indicate confidence that the investigation will clear them. The deceptive person however will often lack the same level of confidence. Be alert to responses such as “I hope it will clear me” or “I think I should be OK” One response I received to this question was “What do you think? Do you think that I will come out OK?”

“Graham, who do you think would eliminate you from suspicion?”

Truthful suspects will usually name individuals who can easily be accessed for verification such as other employees in the area. The deceptive person will offer people who may not at all be connected with the place of employment such as “My mum” or “My priest”.

An interesting variation on the above question is “Graham, is there anyone you know well enough that you feel is above suspicion and would not do something like this?”

Truthful people will usually eliminate individuals from suspicion. For example the truthful person may say “Well I have known Julie for a while and she wouldn’t have taken the money. Paul wouldn’t do it either because he is very honest.” Deceptive responses may include “I don’t really know” or “I’m not sure”. Truthful people will vouch for others or at the least give you an opinion of who may be involved. The deceptive person will not do your job for you and eliminate others. This will only direct attention to themselves which is the last thing they want to do.

The direct confronting question is good for analysing body language and initial responses.

“Leanne, did you take that gold ring from the display cabinet?”

Truthful suspects will offer spontaneous, direct and sincere denials. Truthful people will answer questions directly and be of assistance to you during the investigation. Once again they have no fear because they know they weren’t involved. Deceptive suspects will be evasive and offer weak denials such as “Are you saying that I took that ring”. This is a “buying time” response. The respondent is repeating the question to buy time to think of a suitable answer. Other responses may include:

“Who me?”
“What did you say?”
“How could I have done that?”

Another indicator of a fabricated response is when the deceptive suspect offers qualified denials such as “I swear on the bible I wouldn’t do that” or “I swear to god I didn’t take it”. Be aware when someone enlists the bible, religion or a respected person to demonstrate their honesty or credibility.

As human beings we often rationalise, justify and minimise our behaviour, especially when we do something wrong. I once interviewed a suspect for a rape and asked if he had forced himself onto the victim. His response “I’m a married man with a family. Besides did you see what she looked like?” I didn’t ask this man if he was married with children or to comment on the victim’s physical appearance yet he still failed to answer the question. His rationale was that because he was married he didn’t or wouldn’t have to force himself onto anyone. Diversion and evasion are tools of deceit.

Analysing non-verbal behaviours

As 80% of all human communication is non-verbal we often tend to overlook the importance of analysing body language in context. One of the most common errors in analysing body language is taking one action such as loss of eye contact as deception. What we should be looking for is clusters of body language. If the spoken word is inconsistent with our body language at the time of the response or immediately after then this is significant. When I ask a question such as “Did you forge that signature on the withdrawal slip?” and the response is “Are you asking if I forged someone else’s signature?” at the same time the interviewee starts adjusting clothing or jewellery, crosses their legs, averts their gaze out the window and rubs the back of their neck then this question has caused obvious anxiety. If the person didn’t sign the withdrawal slip then this is not a threatening question.

A good interviewer will be able to decipher non-threatening behaviour before the interview even starts. If after an important question your suspect starts rubbing hands, scratching, stroking or removing imaginary lint from a jumper determine if this behaviour was present earlier. I interviewed one suspect for a number of thefts from a department store. This man was very expressive with his hands during my initial conversation with him. As soon as I asked him a question about the thefts he sat on his hands and started tapping his left foot against the desk.

Other psychological issues

It is important that an interviewer remains impartial and professional. Avoid expressions of disbelief, shock, anger, disgust or scepticism. Remember an investigator’s job is to get to the truth of the matter. If you have built an effective rapport with the interviewee expressing your personal attitudes, revulsion or disgust at their behaviour will only hamper the purpose of the interview.

Allow the interviewee to save face. By calling a sex offender a “rock spider” or a peeping tom a “pervert” you are closing the door before you start. Remember the last time someone was derogatory towards you. Did you become defensive? If the answer is yes then you probably became indignant, angry and resented that person. Would you then respect that person enough to tell them anything of a personal nature? Probably not.

If a suspect walks into my office and offers to shake my hand I have more to loose by not shaking that hand. By refusing to shake that hand I have already shaped that persons perception of me. In order to establish a rapport with a suspect I want that person to like me, not fear me. I have to give that person a reason to confide in me and feel relaxed enough to want to tell me what they did.

John admitted committing 26 of the burglaries that he could remember. He had been interviewed by three other police officers previously. At the end of the interview knowing that I had very little evidence other than his detailed admissions I asked John why he told me and not the other police. His response? “You are the only one who treated me with respect”.

For training courses in behavioural interviewing techniques visit www.polygraph.com.au.