The Murder Book Casebook
Investigation and Psychology
Evidence-based explainers on testimony, memory, deception research and investigative reasoning.
- What Is a Murder Book? The Police Case File ExplainedWhat investigators mean by a murder book, what a homicide case file usually contains, and where the term shows up in crime fiction and games.
- Can You Actually Tell When Someone Is Lying?What decades of research say about how accurately people can tell lies from truths, and why behaviour alone is a weak guide.
- Why There Is No Single Reliable Sign of DeceptionWhy research has found no behaviour that reliably reveals a lie, and why nervous or evasive behaviour has many innocent explanations.
- How Investigators Find Inconsistencies in a StoryA high-level look at how investigators gather an account, test it against what is known and treat inconsistencies with care.
- What Is Cognitive Load in an Interrogation?What cognitive load means in interview research, what the cognitive approach to lie detection proposes, and where the evidence is disputed.
- Interview Versus Interrogation: What Is the Difference?How information-gathering interviews differ from accusatorial interrogations, from the PEACE model to the Reid technique and the research on confessions.
- Open-Ended Versus Leading QuestionsHow open-ended and leading questions differ, what memory research shows about suggestive wording, and why interview guidance puts open questions first.
- Why Truthful Accounts Can Still Be InconsistentWhy a truthful account can shift between tellings, what research says about details remembered later, and when inconsistency does and does not matter.
- Why Innocent People Sometimes ConfessWhat research by Saul Kassin and others shows about why innocent people confess, who is most at risk, and why false confessions are so persuasive.
- How Confirmation Bias Can Affect an InvestigationHow early beliefs can narrow an investigation into tunnel vision, what experiments show about its effects, and which safeguards are proposed.
- What Is an Investigative Timeline?What an investigative timeline is, what it records, how it helps compare accounts, and why its entries must be treated with care.
- How Investigators Compare Multiple AccountsHow investigators compare statements from different people, and why neither agreement nor disagreement settles what really happened.
- Why Memory Is Not a Perfect RecordingWhy human memory rebuilds events rather than replaying them, and what that means for honest witnesses and investigations.
- What Makes a Statement Unreliable?The many reasons a statement can be wrong, from stress and suggestion to source confusion and interview pressure, and why unreliable does not mean dishonest.
- What Is Behavioral Leakage?The origin of the idea that hidden feelings leak through nonverbal behaviour, what the research found, and why leakage is not proof of deception.
- Why People Avoid Answering Questions DirectlyThe innocent and non-innocent reasons people sidestep questions, and why avoidance alone cannot reveal guilt.
- How Repeated Questioning Can Affect MemoryRepeated questioning can bring back genuine details or plant false ones, depending on what the interviewer adds and repeats each time.
- How Stress Affects TestimonyHigh stress tends to make eyewitness memory less accurate, and visible stress in an interview is not a reliable sign of deception.
- What Is the Difference Between a Lie and a False Memory?A lie and a false memory can produce the same wrong statement, but only the liar knows it is untrue.
- How Investigators Test an AlibiInvestigators test an alibi by seeking independent corroboration, but research shows innocent people often struggle to give accurate, well-supported alibis.