Logic, Reasoning, and Human Factors in Latent Print Examination

Vocabulary flashcards covering the logic, reasoning, human factors, and legal standards involved in latent friction ridge impression examination and expert testimony.

Deductive Logic

A form of reasoning that starts with a general rule and applies it to a specific case to reach a conclusion aimed at certainty.

Inductive Logic

A form of reasoning that uses observations and experience to make a likely conclusion based on probability rather than absolute certainty.

Abductive Logic

A form of reasoning that chooses the most likely explanation based on the available evidence, aiming for the best fit.

Categorical Examination Conclusions

Specific determinations such as Identification, Exclusion, or Inconclusive that provide clear yes-or-no answers for the legal system.

Continuous Statistical Conclusions

Conclusions that describe the strength of evidence through statistical data and likelihoods rather than absolute match results.

Likelihood Ratio (LR)

A measure used to describe the strength of fingerprint evidence by comparing the probability of the evidence under two competing explanations.

Posterior Probability

The probability that a suspect is the source of a latent print after considering the fingerprint evidence and other case-related information.

Faulty Reasoning

Drawing a conclusion that does not logically follow from the evidence or using weak and irrelevant connections.

Circular Reasoning

An error in logic where a claim is proven by simply restating it, such as saying an identification is correct because the examiner says it matches.

Transposing the Conditional

The logical error of assuming that if a true conditional statement exists, such as "if two prints come from the same source, they share ridge detail," the reverse must also be true.

Prosecutor's Fallacy

The error of mixing up how rare the evidence is with the actual likelihood that the person is innocent.

Appeal to Authority

The mistake of treating a person's expertise, position, or reputation as proof that a claim is true instead of evaluating the supporting evidence.

False Dichotomy

A logical fallacy that presents only two options when more possibilities actually exist, such as claiming a print is either from the suspect or useless.

Decision-Based Mistakes

Honest errors that occur when an examiner uses their training but reaches an incorrect conclusion due to poor choices or incorrect procedures.

Perception-Based Mistakes

Honest mistakes occurring when an examiner fails to correctly see, notice, or interpret ridge details or features present in a print.

Skill-Based Mistakes

Errors occurring during routine or familiar tasks, often caused by distractions, loss of focus, or memory lapses.

Violations

Intentional actions where an examiner knowingly ignores or departs from established procedures or protocols.

Technical Environment

The tools, equipment, and software used by an examiner that can affect the accuracy and efficiency of fingerprint analysis.

Physical Environment

The laboratory conditions and workspace setup, such as lighting and layout, that affect an examiner's comfort and focus.

Adverse Mental States

Temporary mental conditions like stress or heavy workload that negatively affect an examiner's judgment and objectivity.

Adverse Physiological States

Physical conditions such as fatigue, illness, or strain that negatively affect an examiner's ability to perform accurately.

Cognitive Bias

A psychological influence that can affect judgment and decision-making, such as focusing on similarities while overlooking differences because a match is expected.

Discovery

The phase of a civil lawsuit or criminal proceeding where parties gather information and evidence from each other to build their cases.

Exculpatory Evidence

Evidence that helps the defendant by proving they might be innocent or by creating doubt about their guilt.

Hearsay

A statement made outside of court that is offered in court to prove the truth of the matter asserted, rather than the speaker testifying directly.

In Limine

A pretrial motion asking the judge to exclude or allow certain evidence before the jury hears it.

Nolle Prosequi

A formal notice by a prosecutor that they are dropping or stopping the pursuit of criminal charges against a defendant.

Plea Bargain

A deal where the defendant gives up the right to a trial in exchange for a more favorable outcome, such as reduced charges.

Prejudicial Effect

When evidence or information creates an unfair influence on a judge or jury, causing a decision based on emotion or bias rather than facts.

Probable Cause

The existence of enough facts and evidence for a reasonable person to believe a crime occurred or a suspect was involved.

Probative Value

The usefulness or strength of evidence in helping a judge or jury determine what actually happened in a case.

Prosecutor

The lawyer representing the government who is responsible for bringing criminal charges against an accused person.

Reliability

In scientific terms, the extent to which a method, measurement, or result is consistent, dependable, and repeatable under similar conditions.

Rule 16

A legal rule requiring the government and the defendant to exchange specific evidence and information to prepare for trial.

Summary Judgement

A decision by a judge to resolve a case without a trial because the evidence shows there is no real factual disagreement for a jury to decide.

Voir Dire

The process used to select a fair and impartial jury by identifying potential biases or conflicts of interest.

Rule 401

The federal rule defining evidence as relevant if it makes a fact more or less probable than it would be without the evidence.

Rule 403

The rule allowing a judge to exclude relevant evidence if its value is outweighed by the risk of unfair prejudice or misleading the jury.

Rule 702

The primary federal rule governing expert witness testimony, requiring it to be based on sufficient data and reliable methods.

Rule 901

The federal rule requiring evidence to be authenticated, proving it is what the proposer claims it to be, before it is admitted.

Frye Standard

A legal standard where scientific evidence is admissible only if the method is "generally accepted" within the relevant scientific community.

Daubert Standard

The federal standard requiring judges to act as gatekeepers to ensure scientific expert testimony is both relevant and scientifically reliable.

Kumho Tire v. Carmichael

The Supreme Court case that expanded the Daubert reliability standard to include all types of expert testimony, including technical and specialized knowledge.

Brady v. Maryland

The landmark case requiring the prosecution to disclose exculpatory evidence favorable to the defense.

Giglio v. United States

The Supreme Court case expanding the Brady rule to require the disclosure of impeachment evidence that affects a witness's credibility.

United States v. Henthorn

The case ruling that the prosecution has an affirmative duty to review the personnel files of testifying federal officers for exculpatory or impeachment material.