How best to use evidence in I&I
The Strategic Use of Evidence (SUE)
Last week I was introduced to a concept called the Strategic Use of Evidence (SUE for short). This concept is intuitive and, according to the science, it is one of the most effective methods of detecting deception.1 I plan to use it from here on out. Basically, SUE is a way to use evidence in a way likely to get the maximal amount of information from an interviewee. Rather than confronting a suspect right away with evidence, SUE draws out the delivery of evidence in a way that increases the cognitive load on a deceptive interviewee and forces them to decide what and when to disclose.
If you’ve been a detective for a while, you’ve witnessed firsthand the capacity of liars to lie. When confronted with fingerprints, video surveillance, or DNA showing beyond any doubt that they are the one that did the crime, they’ll look you right in the eye and say, “It wasn’t me.” Then what happens? The detective falls apart because their only strategy was to show them that evidence. There was no backup plan.
When I was a teenager, I worked at a shoe store in the mall. At the time, Shaggy, “It wasn’t me” was on the radio everywhere. I heard it on the drive to work. I heard it all day during work. Then I heard it on the way back. It was awful. I really came to hate that song. We get it! Your girl walked in on you with another girl and you said, “It wasn’t me.” Cute. Looking at it now, though, I see what a good strategy this is when all else has failed. Even against the best evidence, a continued stream of denials will cause even the most sure to double check their facts.
For years now, I’ve advocated using evidence sparingly, only after a good interview, and then in a way that implies much more than there is. Rather than saying, “here’s everything!” you want to say, “here’s a few things we should talk about, we’ll get to the rest later.” Whether you have the goods or not, you should never let the interviewee know the extent of what you have. In general, these presentations end up in arguments. In one of my articles I wrote about how a single piece of evidence is like a drop of water, it can be wiped away (argued about). An undefined mass of evidence is like a tidal wave, there’s too much of it and not one place to direct your defenses.
The video linked below is an example of a traditional presentation of evidence. It’s a little over three minutes, but it’s worth watching. The interviewee is a former Oklahoma Republican congressman now serving time in prison for soliciting a minor. These investigators have him dead to rights (in a hotel room, with the minor, and with the messages laying out all the grooming and sex stuff), but within just 6 and a half minutes of starting the interview (where this clip picks up), they lay out every single piece of evidence they have! For anybody thinking to themselves, “Oh, right on, good technique” wait until you hear his response. “It’s not me.”
This is where SUE comes in. SUE says the best way to use evidence is at the end of an interview and after having supplied the interviewee plenty of chances to explain it. Interviewers can manipulate the suspects’ perception of evidence so that they will share more information. The SUE technique was created by research psychologists Maria Hartwig, Dr. Par Anders Granhag, and Dr. Timothy Luke. Full disclosure: I went to a class and read some pamphlets, this is SUE as I understand it. If there are any discrepancies or incorrect parts, I’m sure the error is mine.
Let’s model how SUE might look in reference to the above case with the congressman. The congressman was found in a hotel room with a minor. Your main pieces of evidence are a witness that has seen the congressman pick up the child and drive him to a hotel and a series of messages from KiK messaging app. The messages show the kid messaging with “Jamie Tilley.” The kid and “Jamie” sext back and forth. Most damning of all, the specific meet up is described and planned on those KiK messages all while the eyewitness watches. Basically, the guy is screwed.
We are confident in the eyewitness account and the KiK messages. The fact of finding the congressman in the room is undeniable (cops, body cameras, etc) so we wouldn’t want to use SUE method on that. However, the eyewitness and the fact that cops have the KiK messages may not be known by the congressman.
First, we want to think of innocent explanations for what the eyewitness saw and what the messages said. This is an essential part of the technique because some suspects are innocent. On the other hand, a deceptive suspect will have gone through the same thought process. Therefore, you’ll be anticipating arguments and defenses they will use.
For what the witness saw: maybe he was just giving the kid a ride. Maybe the kid is on hard times, and he wanted to help him get a hotel room. Maybe the kid is a drug user, and he wanted to give back by getting the kid safe and then into a rehab. Maybe the kid is a family member. Maybe the kid is his long lost son. Maybe the kid is blackmailing him. You see where I’m going with this?
For the KiK messages: maybe it isn’t the congressman. If it is the congressman’s account, maybe somebody hacked it. Maybe his daughter was using the account. Maybe he thought he was sexting with his wife / another man / another love interest.
Once you think of these more innocent explanations, think what you would say to them too.
This part of the process was one of the most eye opening for me. This pre-thought is quick, easy, and very effective at allowing the interviewer to anticipate objections and defenses.
The next step is to notify the subject of the investigation. SUE recommends using language as vague as they will let you get away with. This breaks with my normally forthright approach to notifying people, but this is their technique so let’s hear them out.
Once the subject has come in for an interview, you need to do a thorough interview. The developers of SUE propose using Motivational Interviewing (MI) and Cognitive Interviewing (CI) methods to interview. If you aren’t familiar with those, do your interview the best you can. Build rapport. Ask questions. Look for the truth. Be non-judgmental. If the regular interview doesn’t resolve it, you’ll need to bring out the evidence.
During your interview, you’ll want to gradually bring out the story. Each subsequent question assumes that the suspect has failed to bring up the incriminating issue or contact. These may look like this:
In as much detail as you can, without leaving anything out, please tell me everything about your activities on March 16th, 2017.
Tell me about who else you were in contact with on that date.
Who, if anyone, accompanied you to the hotel that day?
So, just to make sure I have it all straight, on March 16th, 2017 you [recounting of activities that neglect to mention Juvenile]?
So let’s look at strategic questions for the KiK messages.
Including electronically and in person, without leaving anybody out, please tell me all of the people you had contact with on March 16th, 2017.
Was there anybody else?
Who, if anyone, did you communicate with using your phone that day?
To review, you had contact with [list of people and situation] including Juvenile. You spoke to Juvenile on the phone, and you saw him in person, but you did not exchange messages with him in any other way on the phone?
This is where the final phase of the SUE comes in. This is where you disclose evidence using the Evidence Framing Method (EFM). At this point, the interviewee has not been able to resolve the discrepancies between the events and the evidence. This method has you disclose each piece of evidence slowly without naming your sources until the very end. It may look like this.
We have information that you have been in contact with Juvenile online other than phone calls. Please explain what that contact might be.
We understand you’ve used KiK to communicate with Juvenile. Please tell me about that.
A person we believe to be credible reported seeing sexually explicit messages between you and Juvenile on KiK. Can you explain that?
At this stage, you would have the opportunity to say, “We have your KiK messages with Juvenile, and we need to talk about them.” The SUE technique leaves you the option to leave it on the lie. In fact, the technique suggests that an obvious lie that can be proven as such is almost as good as the truth. So if the congressman lies about using KiK to send those messages, and you can prove that he did, his lie is almost as valuable as the truth. In fact, you provided him with numerous opportunities to come clean. That won’t look good for him in court.
As you can imagine, with each question, an interviewee is likely to add information that you didn’t know about and weren’t looking for, which is great! After question 1, for example, you may find out that he chatted with Juvenile on Google Hangouts, which you hadn’t previously known. Follow up on that information as befits your case. Keep working down the list, though, until you get to the specific item, which, in this case, is KiK.
One thing I was instructed on in this method, which bears repeating is that you must avoid making the SUE obvious. Change the way you word your questions. Space the SUE questioning out between other questioning. If the subject feels that you are “doing a trick” on them, they will resist you. A friend of mine brought his wife to a Christmas party. I asked her a question, and she told me, “You’re doing it aren’t you?!? That interview thing!” and she refused to answer. Nobody likes being played with.
There are four phases to the SUE technique.
Prepare for the SUE.
Know all of your evidence as thoroughly as possible
Separate facts from information
Consider all plausible innocent explanations for the evidence
Informing the interviewee
Strategic questions
Disclose evidence using the Evidence Framing Matrix
I want to give a big shout out to my FLETC instructors J. Terland and J. Schanke for putting this class together. I learned a lot.
Keep interviewing. Don’t let the perfect be the enemy of the good. Get in the room and ask those questions.
If you enjoyed this article, feel free to buy me a coffee. No pressure.
“Prior to the interviews, half of the interviewers were trained how to use the SUE technique and were asked to use this technique in the subsequent interview. The other half of the interviewers did not receive training and were instructed to interview the suspects int he manner of their own choice. The untrained interviewers obtained 56.1% accuracy rate which is similar to that typically found in nonverbal and verbal deception research…SUE trained interviewers, however, obtained 85.4% accuracy rate and this is the highest accuracy rates ever reported in this type of deception detection research. Further analyses showed that guilty suspects contradicted the evidence more than innocent suspects, but importantly, particularly when they were interviewed by SUE-trained interviewers.” - Aldert Vrij