Strategic Use of Evidence, In Depth With Examples
Strategic Use of Evidence
“An interview with a suspect has more structural similarities with that of a game in the sense that it relies on the mutual use of strategies to obtain the objective. These strategies and goals that the suspect, particularly the guilty suspect, have…they’re in conflict with the interrogator’s goals.” - Maria Hartwig1
Strategic Use of Evidence (SUE) principles
Liars want to be judged as truthful
Liars will try to figure out what evidence the interviewer has.
Liars will develop strategies to convince the interviewer that they are truthful.
Truth tellers will generally openly report everything with significant details, and cooperate with requests for information. Will readily provide a plausible explanation.
Know your evidence and evaluate it. Resolve to disclose it late if at all.
Every detective should be using the Strategic Use of Evidence (SUE) technique. This technique, identified by Drs. Maria Hartwig, Pär Anders Granhag, and Timothy Luke, is immediately intuitive, science based, and its use extracts the maximum amount of information out of the evidence at hand. Any working detective that hasn’t received training in the SUE technique will have had the experience of presenting fool-proof evidence to your suspect only to have them say, “It wasn’t me” or something similar. If you want to avoid repeating that experience, read on.
The problem with having great evidence is it can make you lazy. “I’ll show him this photo I have, and he’ll have to tell me what happened.” No matter how good your evidence is, the capacity of people to lie is infinite. Never make the mistake of believing that your evidence is so good that it will have to make your guy talk. I don’t care if you have video of him shooting the victim, he’s still capable of denying any involvement whatsoever. You were so excited to get to the evidence presentation that you skipped building rapport, gathering basic facts, and now you’ve accused him and the illusion of cooperation is gone. Big mistake (Pretty Woman vibes).
With the SUE technique, you still get to show him that piece of evidence you’re so excited about, but you have a few extra steps to take. At each step along the way you are almost certain to gather more information. The more information you gather the more likely it is that deceptive suspects will reveal themselves. For the SUE technique to work, you need to have at least one piece of evidence. The evidence you use needs to be the piece that the suspect is least likely to be aware of.
There are four phases of the SUE. First, prepare for the SUE. Note the origin or source of each piece of evidence and identify the strongest pieces. Not all evidence is created equal. An eyewitness and a partial fingerprint are not the same. Consider the possible plausible explanations for the pieces of evidence you will use. I’ve found this step to be the most eye opening for me, causing me to rethink what I think I know about the crime.
In phase one of the SUE technique, you’ll select your best evidence and think of the plausible explanations for it. I think of this as “thinking of the most innocent explanation.” It is actually part of the exercise to think of ways that the evidence might be in the suspect’s favor, even when those explanations seem ludicrous. This seems like a funny thing to do when you have something like DNA from a sexual assault exam or some other surefire piece of evidence, but it is essential to the successful conduct of your interview.
Continuing on with this first phase, develop your initial open ended questions. These will tend to be along the lines of, “In as much detail as possible please tell me about…” Consider other open ended and specific questions that allows you to narrow your focus and exhaust alternative explanations for the evidence without disclosing the evidence. The creators of SUE describe this narrowing of questions as a funnel model where the top of the funnel is vague questions and the narrowing of the funnel is the increasingly specific questions. Question 1 may be “Tell me all about the issue..” Then the final question might be the very specific, “Were you at the warehouse at 1401 Airport Rd this past Saturday at 8pm?”
The final step of phase one is to plan how you will disclose the evidence. The creators of the SUE discuss using the Evidence Framing Matrix - start vague about the evidence’s source, providing low specificity and end identifying its source precisely with greater specificity. If this seems like a lot of information, don’t give up! This process quickly becomes second nature. Besides, anything is better than simply walking in the room and showing the suspect what you’ve got.
Phase two of the SUE is to inform the suspect of the investigation and get them in the room. Note how this comes after you’ve done all the groundwork. Although I’ve had numerous instances where suspects refused to come in and my preparation didn’t have the payoff I’d hoped for, I saw each of those times as getting a rep in so I’d be stronger for the next one. I’ve had other instances where the suspect demands to come in immediately. If you have done the groundwork in phase 1, you’ll be happy to say, “Sure, I’m available now!” If you haven’t, well, you’ll have however long it takes the suspect to get from where they are to where you are to prepare. I cover my approach to contacting the suspect in a different post. I’ll skip phase two in the exercises below.
Phase three of the SUE is the strategic questioning phase. Here you gather the suspect’s story providing them as many opportunities as possible to admit to the evidence you have and provide their own explanation for it. Start by asking your initial open ended question; explicitly request detail. Ask other open-ended and specific questions (funnel-type questioning model) and continue explicitly requesting detailed responses. These commit the interviewee to their answers. If the interviewee has come with the intention to deceive, this drilling down into their story will increase their cognitive load, which is where mistakes get made. Be listening for evidence of those mistakes like lies of omission, avoiding the issue, and direct denials.
Phase four of the SUE is where it all pays off. This phase is where you will use the Evidence Framing Matrix (EFM) to incrementally introduce the evidence. Begin by disclosing your evidence only vaguely, with low specificity. I think of this as phase four, move one. Then disclose the evidence less vaguely with a higher level of specificity. This would be phase four, move two. The final disclosure should be precise with high specificity. This is phase four, move three. Move one is vague. Move two is more specific. Move three is very specific. The explanation you receive may yield more information or a denial that your evidence contradicts.
Look back at the quote that I started this post with: you have strategies and the interviewee has counterstrategies. Unless he plans to engage in total denial, the deceptive interviewee is sure to have employed the counterstrategy of thinking of an innocent explanation for their actions. When you have employed the same strategy, you are likely to come up with the same excuses that they came up with. Another important aspect of this step is that it opens your mind to the possibility that the suspect IS innocent. Once you think of a few innocent explanations, you may find yourself wondering how strong your case really is. This is a good thing.
Let’s look at some scenarios. Read through these. Below the scenarios, I go into great detail on how to apply the SUE technique to them. Then, I provide a scenario that you can do the work on.
Scenario - Sexual Assault (Adult)
On Sunday, May 15th, Ben called the City Police from his hotel room downtown. Ben reported to officers that he thinks he was sexually assaulted the night before. After finishing up at his conference on Saturday, he hit the hotel bar with his coworker. While at the bar, he struck up a conversation with the bartender, Will. Much later, around 1:45 am, as the bar closed, Ben was fading in and out. Ben remembered Will and his coworker Angela helping him walk up to his hotel room. When they got to the door, Angela left. Ben remembers Will walking him inside and helping him to sit on the bed. Ben reported that he remembered staring at his shoes wondering how he’d get them off of his feet when he felt Will rubbing his penis from on top of his pants. Ben told him “no.” Ben didn’t remember anything else. When he woke up that morning, he saw that his pants were neatly folded on the ground in a way that he would never have placed them. Ben was uncomfortable about Will rubbing his penis, but he was more concerned that maybe Will raped him anally.
As the detective, you gathered video surveillance and receipts from Saturday. The receipts showed that Ben settled his tab around 1 am. The tab showed that Ben ordered a half dozen beers and two shots. The video showed that Ben talked exclusively with Will and his coworker Angela. On one occasion, you can see that Ben touches Will’s hand as he leans across the bar and appears to whisper something in Will’s ear. They both laugh. This is about 1:30 am. On the video you can see that when the trio left the bar, Ben was stumbling as Will and Angela alternately lifted him from under his arms and pulled on his shirt to keep him moving forward. The video showed them getting on the elevator together, getting off the elevator on Ben’s floor, and going all together to Ben’s door. Angela left right away. Will left about 20 minutes later.
You interview Angela. She tells you that Ben is married to a woman named Cynthia, and they have two children. She’s always understood him to be heterosexual. Angela remembered Ben whispering in Will’s ear, because she felt self conscious as though they were laughing at her. She didn’t know what Ben said to Will. Angela stated that she left the room because Ben was much bigger than her, and Will was plenty strong enough to get him inside. She had a lot to drink Saturday night, too. When she left Ben’s she went straight to her room and to sleep.
Scenario - Aggravated Assault
On Wednesday, January 7th, City Police received a call for assistance at 701 Overby St. Jamal, the caller, found his neighbor Martin crumpled up in a puddle of blood inside Martin’s house. Jamal reported that he had been passing by Martin’s house when he saw the door ajar. This was unusual, so he went to check on Martin. At the door, he could see inside where Martin lay. Jamal checked to make sure that Martin was alive, which he was, and he called the police. While waiting for police, Jamal noticed that Martin’s left eye was black and his nose appeared to be broken. Jamal put Martin in the rescue position. Looking about, Jamal was surprised to see how messy Martin’s house was. There were dirty clothes and empty vodka bottles everywhere.
Martin was transported to the hospital. You started out at the crime scene. While there, you noticed that there was a broken shovel in front of the porch. There was a blood trail leading from the porch into the house. While asking follow up questions, Jamal reveals that he and Martin have the same landlord, Julian. A few days before, on Sunday, Jamal heard Julian yelling at Martin for not paying his rent. The argument got more and more heated until Jamal heard Julian shout, “You’ll have your shit out by tomorrow, or you’ll regret it.”
At the hospital the next day (Thursday), you find that Martin has a broken skull on his left side and a broken nose. Martin is groggy. He says that he doesn’t remember anything from Wednesday. He said that he is out of work at the moment. Without a regular schedule, he usually has a few mixed drinks before noon. He remembered the argument with Julian. He also remembered that he had an appointment to see Julian on Wednesday, but he couldn’t say whether or not Julian ever came over.
Scenario - Sexual Assault of a Child (Historical)
On Saturday, March 3rd, City Police responded to 1901 E St Johns Ave on a call of a sexual assault. There, officers met with Maria, who tearfully reported that her daughter, 15 year old Emilia, had just told her about having been raped in July of the previous year. Maria reported that she had been arguing with Emilia about not cleaning her room when Emilia said, “You wouldn’t talk to me like that if you knew what your brother did to me!” Maria asked what she meant, which led to the outcry. Maria told officers that Emilia said that Maria’s brother Roberto, Emilia’s uncle, pulled Emilia into his room and started kissing her. Emilia wouldn’t tell Maria all that happened, but she knew that Roberto put his penis in Emilia’s vagina.
On Tuesday, March 6th, Emilia was forensically interviewed. During that interview, Emilia reported that her uncle Roberto raped her after the rosary service for her grandmother. Although she didn’t remember the exact date, she knew that the rosary was in July and that her grandmother was buried the next day. After the Rosary, the family gathered at Roberto’s. As Emilia came out of the bathroom, she came face to face with Roberto as he stood in the doorway to his room. Roberto told her to come see the surveillance system he had set up on a big screen TV in his room. Emilia walked into his room. Once she was in, she saw that the TV was playing surveillance footage feed from at least four different cameras that seemed to be on the outside of the house. She was surprised when Roberto grabbed her by the upper arms. He pressed his body against hers, and she could feel what she believed was a gun in his waistband pressing into her. She froze. Roberto pushed her onto the bed, pulled her pants down, and he vaginally raped her. Afterwards, he told her to clean herself up and not tell anybody. He said that it would be their secret.
Refer back to the adult sexual assault scenario. In that scenario you have two pieces of evidence that we will consider here. You have video surveillance showing Will the bartender helping Angela the friend carry Ben up to his room. You have Ben remembering Will rubbing his penis from on top of his pants. If you’re Will, and you agree to talk, you have four main strategies: 1) total denial 2) I helped him to his room, and then I left. 3) “I thought he was into me, and I shot my shot (made my move). He said ‘no,’ and I left.” 4) “We had sex, and it was totally consensual.”
As to the video surveillance, the most innocent explanation is that he helped a drunk patron up to his room. Maybe Ben invited him up for an after party. Otherwise, Ben might have invited Will upstairs to hook up.
As to Ben remembering Will rubbing his penis, what are some innocent explanations for this? Maybe Ben is lying. Maybe Will thought Ben was interested in hooking up. Possibly Will helped Ben get his pants off so that he could be comfortable and the rubbing was just a misunderstanding.
Now come up with questions that allow you to anticipate these innocent explanations. Deceptive suspects tend to change their game plan once their first plan falls apart. Let’s say Will’s first plan is total denial. Then, when he realizes that you have him on surveillance video, he may decide to switch to a consensual hook up. However, if you place questions early in the interview that anticipate later defenses, you will make it either impossible or, at the very least, implausible when they switch their strategies.
For example, the surveillance footage explanations hinge on what Will’s thoughts are regarding Ben. When you plan your questions out, you might include, “Were you ever under the impression that Ben was hitting on you?” “What’s Ben’s home life like?” “Were you attracted to Ben?” “How did Ben get up to his room?”
As to the penis rubbing, you might plan some questions like, “Were your hands ever in contact with Ben’s penis?” “How did Ben get undressed?” “What did you do while you were in the room?” “Would Ben have any reason to want to see you get in trouble? (This anticipates the “Ben is lying” defense)” You’ll include these anticipatory questions in your question list. However, you’ll only use them if they aren’t addressed in step two of the SUE technique.
Phase three of the SUE technique is to gather the suspect’s narrative. This should take place with open questions, continuers, reflections, and summations. Your question to Will might be, “If you could, in as much detail as possible, please tell me all about Saturday, May 14th from beginning to end without leaving anything out.” Once he starts talking, be quiet until he finishes. Do not interrupt no matter how much you want clarification. Prompt him to continue talking with continuers like “go on” and “and then?” You might then ask, “What else happened?” Then, “you said that you served several different customers?” Keep prompting him to add more until he appears to have nothing else to add.
If Will hasn’t mentioned walking with Ben up to his room or rubbing his penis, you’ll use the funnel strategy of vague questions leading to specific questions to address that. You might ask, “Where did you go immediately after work?” If he doesn’t mention Ben, you might ask, “Did you spend time with any customers after work that day?” Then, “Did you spend time with Ben after work that day?” Pick one or two major parts of the story to funnel down into in this way. If Will had a consensual sexual encounter with Ben, he should readily admit to spending time with him after work. If Will chooses not to disclose spending time with Ben, it won’t be because you failed to give him the chance.
Then summarize the suspect’s story. “Correct me where I’m wrong. You said … and … you said you spoke to… and then after work you… what did I miss?” He will likely add a few details. If anything he says conflicts with what you know, do not rush to present him with the evidence. That will come later.
Once you’ve gathered the suspect’s story, now is a good time to use those questions you came up with in the preparatory stage. If the suspect didn’t already address them, ask him those questions now. For example, if Will didn’t say anything about Ben hitting on him, you’re going to want to ask if he did or not. If Will says Ben hit on him, you’ll have more to talk about. If he denies it, you’ll have put him in a very difficult position later on should he attempt to swivel to, “Ben and I hooked up and had consensual sex.”
Now we come to phase four in the SUE technique. This is where your hard work pays off with a lot of information. You’ll ask about your evidence starting with vague assertions and moving onto the ever more specific reveal of evidence. This will usually take place in three moves, which we will look at by considering the video surveillance showing Will taking Ben into his room. You would follow this process if Will has denied or omitted that he went into Ben’s room.
SUE technique, phase four, move one: “I have some evidence that you went into Ben’s room that night. Tell me why that would be.” Here we come to a fork of possibilities. Either he denies that such is the case or he provides more information. If he adds information, he might say something like, “Maybe I went into his room for a minute, I hardly remember.” If he is adding information, take the time to explore that. Once he has stopped adding new information, move onto the next step.
SUE technique, phase four, move two: “In fact, I have a witness that saw you take Ben into his room that night. Why would that be?” This requires some flexibility because Will might have admitted after step one that he went into Ben’s room for a few minutes. You might adjust your question to say, “In fact, I have a witness that saw you go into Ben’s room and stay in there for almost 20 minutes. Why?” Even if you didn’t adjust the question, you’ll create anxiety in a deceitful Will by introducing a witness. Again, you have reached the fork. Either he continues to deny or he adds more information.
SUE technique, phase four, move three: “Actually I have surveillance video that shows you carrying Ben into his room and then staying there for almost 20 minutes. Can we talk about that?” Here you have reached the most specific point. This is the point where untrained detectives start. The untrained detective might start the interview by saying, “Here’s surveillance footage of you carrying Ben into his room. Do you deny it?”
It’s important to point out that your interviewee may have freely admitted to the events described by the evidence you have. If that happens, just skip that piece of evidence. You can’t squeeze blood from a stone. Carry on with the other evidence you have.
Can you see how much more information is likely to be gathered from the same evidence by using the SUE technique? Have you, like me, ever walked into a room, presented your best evidence, and been surprised at the continued denials? If you’re like me, you’ll be sold on this process immediately.
What I like most about the SUE technique is that it is devastatingly effective against deceptive subjects while also providing the maximum opportunity for innocent subjects to provide evidence of their innocence. I have had cases where the guilt of the suspect seemed certain when I walked into the room, but, because I provided them a fair opportunity to explain themselves, they were able to provide evidence that led to their exoneration. We are in the business of investigating. We should not be anxious to convict or to exonerate. We should be diligent in seeking the truth, whatever that may be. The SUE technique is an important tool for us to use.
Let’s process through the SUE technique for each of the other scenarios in this book. First, the aggravated assault. If you’ll look back at that case, you’ll see that there are a few pieces of evidence that stand out. Let’s focus on one of them. There was the argument between Julian and Martin that Jamal overheard. In that argument, Jamal heard Julian yell, “You’ll have your shit out by tomorrow, or you’ll regret it.” In this case Martin doesn’t remember what happened that led to his having a skull fracture and a broken nose. A quick consideration of the case suggests that either Julian met up with Martin and assaulted him or Martin, a likely alcoholic, fell and injured himself. The assault is more likely, but the accidental injury isn’t impossible. Your interview with Julian will be a major part of the investigation.
SUE technique phase one. What is the most innocent explanation of the argument (or what are other plausible explanations)? Perhaps Jamal is lying about Julian. Or maybe it happened, but Julian never intended to follow through on the threat. Maybe Jamal misheard. Could it be that it was actually Martin threatening Julian?
Develop anticipatory questions. “Is there any reason that Jamal would want to see you get in trouble?” “Are there any problems between you and Jamal?” “Describe any arguments you’ve had with Martin.” “Any others?” “Have you ever caused injury to Martin?” “How would you describe your relationship with Martin?” “Has Martin ever threatened you?”
SUE technique phase three. Gather the suspect’s narrative. “In as much detail as possible, without leaving anything out, please describe your activities on Wednesday, January 7th.” Whatever he tells you, you’ll follow up with questions to get more. “What else happened?” “Where else did you go?” “Who else did you talk to?” If he doesn’t mention being at Julian’s Then you’ll summarize, “Correct me where I’m wrong. I heard you say that…What did I miss?” At this point, you have the full narrative. Time for step three.
SUE technique phase four, move one: “I have some evidence that you argued with and threatened Martin a few days before he was injured. Tell me about that.” Here Julian will either deny that it happened, or he will add additional information. If he adds information - even if it is to say somebody must be lying on him - develop that information until you know all he is willing to tell you.
SUE technique phase four, move two: “In fact, I have a witness that heard you argue with and threaten Martin. Please explain that to me.” He will deny or add information. If he adds information, explore it.
SUE technique phase four, move three: “Jamal, Martin’s neighbor, has provided a sworn statement that you argued with and threatened Julian. Let’s talk about that.” Julian will either deny or add information.
If Julian hasn’t answered all of the anticipatory questions that you developed, ask them now.
Finally, let’s consider the historical child sexual abuse case. As with all of these types of cases, hard evidence is scant. If you’ll look back at the case study, you’ll see that Emilia has made an outcry to police that her uncle Roberto raped her in his room in July of the previous year after her grandmother’s rosary. I’m going to suggest using part of Emilia’s statement from the forensic interview as evidence.
SUE technique phase one. What is the most innocent explanation for Emilia accusing Roberto of raping her? What are plausible explanations for the evidence (whether they say what we “want” them to say or not)? Perhaps Emilia is lying. Maybe they had sex, but it was consensual? Perhaps Emilia is out to get him.
Now develop anticipatory questions. “Would Emilia have any reason to lie about you?” “Can you think of any reason Emilia would have to get you in trouble?” “Have you ever had any sexual contact with Emilia?” “What’s the biggest lie Emilia has ever told?” “Have you and Emilia argued about anything recently?”
SUE technique phase three. Gather the suspect’s narrative. “Please tell me everything that happened after the rosary in as much detail as possible.” Prompt the suspect with continued requests for information using as many open questions as possible. If he doesn’t include contact with Emilia, Emilia being in his room, or, indeed, sex with Emilia, you can funnel down into those questions. As to Emilia being in his room, you could prompt him, “Please tell me all of the people that were in your room throughout the night.” Then, “Was there anybody else?” You want to follow the technique down into the specifics. Then summarize. “Ok, I heard you say… what did I miss?” Now you have all of Roberto’s story that he’s willing to share with you.
SUE technique phase four, move one: “I have evidence that you had sexual contact with Emilia on the night of the rosary. Tell me about that.” He will either deny or add information. If he adds information, like, say, “Maybe I brushed against her chest or something,” have him tell you as much as he is willing to about that. Then move on.
SUE technique phase four, move two: “I have a witness that has made a sworn statement that they know you had sexual contact with Emilia that night. Why is that?” They will deny or add information.
In instances like this when the evidence you have comes down to the victim’s statement, I have opted to leave out move three because I consider it too easy to deny by saying, “Well of course she’d lie…” The presentation of this evidence is effective because it makes the suspect think that maybe he told somebody and they are informing against him as well as the victim. I think stopping after move two achieves the maximum squeeze out of that piece of information without the relief that it may provide the suspect to know that he is still against one accuser instead of two.
As with the other examples, look over Roberto’s statement and see if you need to ask any of your anticipatory questions. If you do, now is the time.
Use the following (brief) scenario to practice the SUE technique: a woman is stabbed at the local homeless shelter. Jeremy and Jenny, two eyewitnesses, have indicated that Raven stabbed the victim. Further, you have video surveillance showing Raven fleeing the scene after the stabbing happened. You have collected a bloody knife in the path that Raven is known to have fled along.
Phase one:
What evidence do you have?__________________________
Rank the evidence from best to worst. _______________________
Choose your best piece of evidence. What is it? ______________
With your best evidence, what are plausible explanations of that item (don’t hesitate to list explanations that rule Raven out as the suspect)?______________________
If Raven wanted to deceive you about that item, what might she leave out? ______________________
What question will you ask to prompt Raven’s accounting for her actions that night? _____________________________
Look back at your list of plausible explanations. What anticipatory questions might you ask that would allow Raven to invoke that defense (or, alternately deny it)? ______________________________
How will you disclose the evidence in phase four during the Evidence Framing Matrix (EFM)? What is move one (the broadest question)? What is move two (the narrowed question)? What is move three (the most specific question)?
Phase two is contacting the suspect.
Phase three is gathering the suspect’s narrative.
What question will you ask to prompt Raven’s recall of that night?
If Raven doesn’t bring up being at the homeless shelter, what questions will you ask to funnel down to the point where you ask her directly?
If Raven doesn’t mention stabbing the victim, how will you funnel down towards that?
If Raven doesn’t mention Jeremey and Jenny, the two eyewitnesses, how might you prompt her to discuss them?
If Raven doesn’t mention running away from the homeless shelter, how might you prompt her to bring that up?
Phase four is using the Evidence Framing Matrix (EFM) to present your evidence.
Using the piece of evidence you selected, what is your move one question?
What is your move two question?
What is your move three question?
If you are more of a visual learner, watch this video of detectives interviewing Ralph Shortey, and Oklahoma politician accused of soliciting a minor for sex. The clip starts at about 6:28 seconds into the interview. You’ll see the detectives lay out all of their evidence for free. Now that you know what the SUE technique is, how much of a wasted opportunity does this seem to be? How might you approach that evidence knowing what you know now?
To summarize: the SUE technique is a science based process for extracting the greatest amount of information from the evidence you have. The technique takes place in four phases. Phase 1 is thinking of plausible and / or the most innocent explanation for the evidence. This phase also includes pre-planning questions including those that prompt the narrative (big, open questions) and those that drill down into the narrative. You should also develop anticipatory questions that head off potential excuses. Phase 2 is contacting the suspect. Phase 3 is gathering the suspect’s narrative of events. Phase 4 is the presentation of evidence starting from vague to more and more specific.
If you found this useful, feel free to buy me a coffee. No pressure at all.
YouTube interview with Maria Hartwig on the SaltCubeAnalytics channel