The Murder Book Casebook
Interrogation Methods
- What Is Baiting in an Investigative Interview?Baiting in an investigative interview is a technique in which the interviewer implies that incriminating evidence exists, without revealing what that evidence actually is, in order to observe how the
- What Does Commit to Detail Mean in an Interview?"Commit to detail" is an interview strategy in which the interviewer encourages or requires the subject to provide specific, concrete details about their account, rather than allowing vague or general
- What Is Cross-Examination During an Investigative Interview?Cross-examination during an investigative interview refers to the practice of testing a subject's account by probing it for weaknesses, contradictions and unsupported claims. Unlike cross-examination
- Why Do Investigators Ask the Same Question in Different Ways?Investigators ask the same question in different ways to test whether the subject's account stays consistent or shifts depending on how the question is framed. The reasoning is that a truthful person
- Why Do Investigators Ask Unexpected Questions?Asking questions that a person has not prepared for is one of the more promising interview techniques in deception research. The logic is straightforward: a truth teller can draw on genuine memory to
- Why Ask Someone to Tell a Story Backwards?Asking someone to tell a story backwards is an interview technique designed to increase the mental effort of recall. The idea, developed by Aldert Vrij and colleagues at the University of Portsmouth,
- Why Do Investigators Ask Suspects to Demonstrate What Happened?Investigators sometimes ask a suspect or witness to physically show what happened rather than just describe it. The reason is that demonstrating an action, drawing a scene or sketching a layout requir
- Why Ask a Suspect for Precise Details That Can Be Checked Later?When investigators ask a suspect for precise details that can be checked later, they are using a principle that deception researchers call the verifiability approach. The logic starts from a dilemma t
- What Is the Verifiability Approach to Lie Detection?The verifiability approach (VA) is a verbal lie detection method built on one core idea: truth tellers naturally include more details that an investigator could check, while liars tend to fill their a
- What Is Reality Monitoring in Deception Research?Reality monitoring (RM) is a theory about how people tell the difference between things they actually experienced and things they only imagined, dreamed or were told about. Psychologists Marcia Johnso
- What Is Statement Validity Assessment?Statement validity assessment (SVA) is a structured procedure for evaluating whether a verbal statement is based on a real experience or has been fabricated. It was developed in German-speaking countr
- What Is SCAN Statement Analysis, and Does It Work?SCAN (Scientific Content Analysis) is a statement analysis technique developed by former Israeli polygraph examiner Avinoam Sapir. It claims that truthful and deceptive people use language differently
- What Is Minimization in an Interrogation?Minimization is an interrogation technique in which the interviewer downplays the seriousness of the offence, offers sympathy, suggests face-saving excuses, or provides moral justifications for the su
- What Is Maximization in an Interrogation?Maximization is an interrogation technique in which the interviewer exaggerates the seriousness of the offence, overstates the strength of the evidence and emphasises the severity of potential consequ
- What Is a False-Evidence Ploy?A false-evidence ploy is a tactic in which an interrogator claims to possess incriminating evidence that does not actually exist. The interviewer might tell a suspect that their fingerprints were foun
- Why Can False Evidence Increase the Risk of False Confessions?False evidence increases the risk of false confessions because it convinces innocent suspects that the case against them is so strong that denial is pointless. When an interrogator claims to have fing
- What Is an Information-Gathering Interview?An information-gathering interview is an investigative conversation designed to collect accurate and complete accounts from a witness, victim or suspect. Rather than pressing for a confession, the int
- Accusatorial vs Information-Gathering InterrogationAccusatorial and information-gathering interrogation represent two fundamentally different ways of questioning a suspect. Accusatorial methods, such as the Reid Technique widely used in North America,
- What Are the Mendez Principles on Effective Interviewing?The Mendez Principles are a set of six principles on effective interviewing for investigations and information gathering, published in 2021. They were developed by an international steering committee
- PEACE Model vs Reid Technique: What Is the Difference?The PEACE model and the Reid Technique are two widely discussed frameworks for questioning suspects, and they take opposite approaches. The Reid Technique, dominant in North American police training s
- Why Don't Investigators Reveal All Their Evidence Immediately?Investigators often delay revealing what they know because early disclosure lets a suspect tailor their account to fit the evidence. By holding back key facts and asking open questions first, an inter