Strategic Use of Evidence (SUE) is a research-based suspect-interviewing technique that asks a deceptively simple question: when should you tell the subject what you already have? The answer — later than most interviewers do, and in a planned sequence — produces a measurable improvement in deception-detection accuracy and stronger, more defensible interview records.
Strategic Use of Evidence emerged from a sustained line of research led by Pär Anders Granhag, Maria Hartwig, and colleagues, beginning in the early 2000s. The research program was a direct response to a long-standing problem in the field: lay people, and most professionals, perform only slightly better than chance at detecting deception from behavioral cues alone.
Granhag and Hartwig reframed the problem. Instead of asking what cues distinguish liars from truth-tellers, they asked what behavior interviewers could elicit that would distinguish them. The answer that emerged from a decade of laboratory and field research was a structural change in how evidence is used during the interview itself.
SUE is now one of the most empirically supported suspect-interviewing techniques in the world, and it has been adopted in interview training programs across Europe, North America, and Australia.
SUE rests on a single behavioral insight. A guilty subject who knows what evidence the investigator has will craft an account that fits that evidence. A guilty subject who does not know what the investigator has will craft an account that fits what they think the investigator might have — and will frequently get it wrong, producing statement-evidence inconsistencies that an innocent subject does not produce. An innocent subject, who is simply describing what happened, has no incentive to manage information they don't know exists, and so their account aligns with the evidence almost incidentally.
The diagnostic value of the interview, in other words, comes from the gap between what the subject says and what the investigator already knows. To preserve that gap long enough to use it, the investigator has to resist the urge to confront — to lay the cards on the table early. The technique is named for that discipline: the strategic use of evidence is, above all, the patient use of evidence.
SUE is not a "gotcha" technique. It is a structured way to give a subject the room to commit to an account before they know what they have to align with — and to compare what they say against what the case file already shows.
SUE is conducted as a structured interview, not a spontaneous trick. The sequence below is the form most commonly taught and is the one ASC uses in its training. Each stage has a specific purpose and is documented as part of the case record.
The investigator inventories every piece of evidence: physical, digital, witness, surveillance. Each item is rated for source reliability, specificity, and risk of disclosure. The interview plan is built around which items will be held back and which can safely be referenced early.
A genuine rapport phase, followed by an open invitation for the subject to tell the story in their own words, uninterrupted. The interviewer listens for the shape of the account: what is included, what is omitted, what is volunteered.
Targeted, open follow-up questions explore the regions of the account where the investigator has evidence — without revealing what that evidence is. The goal is to lock the subject into specifics: times, locations, sequences, presence of others. The interviewer is not arguing; they are listening.
Evidence is introduced in a deliberate sequence — typically least-to-most incriminating, or in an order that lets each new item test a specific portion of the account. After each disclosure, the subject is given an opportunity to explain. The investigator documents both the evidence shown and the response given.
A clean close: the subject is given a final chance to add or amend, the interview is summarized, and the record reflects exactly which evidence was disclosed and at which point. That paper trail is the primary downstream value of SUE — it gives prosecutors and triers of fact a clean record of what the subject said before they knew the case.
Across multiple controlled studies, interviewers trained in SUE have produced deception-detection accuracy meaningfully higher than untrained baselines and higher than confrontational protocols. The mechanism is not that the interviewer becomes a better lie-detector; it is that the structure of the interview produces a more diagnostic record. Statement-evidence inconsistencies are objective and reviewable; "gut feel" cues are not.
A second, related effect appears in the population of innocent subjects. Because SUE delays accusation and gives subjects unbroken room to provide their account, innocent subjects are less likely to be coerced toward false admissions and more likely to leave the interview with their credibility documented rather than damaged. The protocol's defenders, including its principal researchers, point to this two-sided benefit — better detection of deception, better protection of the innocent — as the reason it has spread so quickly through evidence-based interviewing programs.
Where confrontational techniques tend to produce admissions of varying reliability, SUE produces records of varying conclusiveness — but the records reflect what was said, when, and against what evidence. That is the kind of record that holds up in court.
SUE is not a substitute for due process. Miranda warnings, custody status, voluntariness, attorney presence, and recording requirements all apply on their normal terms. The technique works inside those constraints, not around them. In a custodial interview, planned disclosure is sequenced after rights have been waived; in a non-custodial interview, the same sequencing applies with no rights threshold to clear.
SUE also requires careful handling of confidential sources, ongoing investigations, and discovery obligations. Withholding a piece of evidence during interview is a tactical choice; it does not change the prosecution's downstream duty to disclose. Investigators have to know, in advance, which items can be referenced openly, which can be alluded to without compromising sources, and which cannot be raised at all without coordination with the prosecutor.
Done properly, SUE produces an interview record that survives challenge — because every disclosure is planned, documented, and tied to the evidentiary inventory built before the interview began.
ASC teaches SUE as a core component of two flagship law-enforcement programs: From Information to Evidence, which focuses on how investigators move case material through the interview to produce admissible, defensible records, and The Academy, ASC's most advanced practitioner certification.
Instruction covers the underlying research, the five-stage sequence, evidence-inventory worksheets used in real cases, and extensive supervised role-play with feedback. Students practice both ends of the table — running the interview and being interviewed — so they can feel the structural difference between a confrontational interview and a SUE-structured interview from inside the chair. Integration with the rest of the ASC framework is explicit: Teach to Talk® rapport opens the conversation, the Adaptive Strategies Compass™ guides real-time choices, and SUE structures the disclosure of what the case file already shows.
The discipline ASC asks of its graduates is the discipline the research demands: do not show your hand until you have given the subject the room to commit to an account. The interview that follows tells you what you need to know.
SUE is taught in From Information to Evidence and refined in The Academy.