BCI Interview - Latent Fingerprints

ACE-V

The acronym for Analysis, Comparison, Evaluation, and Verification; an examination methodology.

ADAMS

The acronym for Authenticated Digital Asset Management System; browser-based application used for the storage, tracking and organization of digital images in case documentation.

AFIS

The acronym for Automated Fingerprint Identification System, a generic term for a finger/palm print matching, storage, and retrieval system.

Alternate light source (ALS)

A light source used to excite luminescence of latent prints, body fluids, chemical reagents, etc.

Analysis

The first step of the ACE-V method. The interpretation of observed data in a friction ridge impression in order to categorize its utility.

Anatomical source

An area of friction ridge skin from an individual from which an impression originated.

Anchor point

A feature present in the latent print that allows an examiner to reliably determine the anatomical location of the unknown impression. Usually a core or a delta but can also be a major crease, a vestige, or some other characteristic ridge flow to assist during comparison.

Arch

A pattern type in which the friction ridges enter on one side of the impression and flow, or tend to flow, out the other side with a rise or wave in the center.

Artifact

Any information not present in the original object or image, inadvertently introduced by image capture, processing, compressions, transmission, display, or printing.

Bifurcation

The point at which one friction ridge divides into two friction ridges.

Blind verification

A type of verification in which the subsequent examiner(s) has no knowledge of the original examiner's decisions, conclusions or observed data used to support the conclusion.

Characteristic

Distinctive details of the friction ridges (also known as features).

Clarity

Visual quality of a friction ridge impression.

Comparison

The second step of the ACE-V method. The search for and detection of similarities and differences in observed data between two potentially corresponding friction ridge impressions.

Competent

Possessing and demonstrating the requisite knowledge, skills, and abilities to successfully perform a specific task.

Conclusion

Determination made during the evaluation stage of ACE-V, including source identification, support for same source, inconclusive, support for different source and source exclusion.

Conflict

A condition in which two or more examiners disagree on a sufficiency decision or source conclusion.

Control

A known standard or preparation for checking or verifying a test reagent.

Core

The approximate center of a fingerprint pattern.

Correspondence

An observation of the type, orientation, and relative spatial relationship of friction ridge details and other information in agreement; an accumulation of similarities between two impressions resulting in an overall conformity or agreement.

Crease

A line or linear depression on palmar and plantar surfaces that accommodates flexion. These include major (primary) creases which form prior to ridge development and secondary creases, also referred to as “white lines“ which form after ridge development.

DCS5

The acronym for Digital Capture System; hardware/software system produced by Foster+Freeman used for digital photography complemented with enhancement software which can store, track and organize digital images for case documentation.

Delta

The point on a friction ridge at or nearest to the point of divergence of two type lines, and located at or directly in front of the point of divergence.

Discrepancy

The presence of friction ridge detail in one impression that does not exist in the corresponding area of another impression.

Discriminability

The degree to which information in an impression can be used to reliably distinguish between impressions made by different sources. The _____ of an impression encompasses its features’ quantity, spatial arrangement, clarity, and rarity.

Dissimilarity

A difference in appearance between two friction ridge impressions.

Distortion

Variances in the reproduction of friction skin caused by factors such as pressure, movement, force, and contact surface. (See also Appendix V).

Elasticity

The ability of skin to recover from stretching, compression, or distortion.

Elimination prints

Exemplars of friction ridge skin detail of persons known to have had legitimate access to an object or location.

Evaluation

The third step of the ACE-V method. The weighting of the aggregate strength of the observed similarities and differences between the observed data in the two friction ridge impressions in order to formulate a source conclusion.

Exemplars

Recording of the friction ridge skin of an individual registered electronically, by ink, or by another medium (also known as known prints).

Fingerprint

An impression of the friction ridges of all or any part of the finger.

Focal Points

A feature used to limit search parameters, including but not limited to the core, delta, creases, target group, scar or other distinctive ridge flow.

Friction ridge

A raised portion of the epidermis on the palmar or plantar skin.

Friction ridge detail/Features

The combination of ridge flow, ridge characteristics and ridge structure of friction ridge skin, as observed and reproduced in an impression.

Furrows

Valleys or depressions between friction ridges.

Hypothenar

The ulnar side of the palm below the distal transverse crease.

Impression

Friction ridge detail deposited on a surface or the result of ridge detail removing a matrix from a surface.

Incipient ridge

A friction ridge not fully developed that may appear shorter and thinner than fully developed friction ridges.

Incomplete

The determination during comparison that the exemplars are inadequate in either quantity or quality.

Inconclusive

The conclusion that the observations do not provide a sufficient degree of support for one proposition over the other. Any use of this conclusion shall include a statement of the factor(s) limiting a strong conclusion.

Insufficient ridge detail

An impression(s) of the friction ridge skin that does not contain sufficient data to support a reliable conclusion. Also reffered to as no value.

Interdigital

The region of the palm distal to the ulnar side of the distal transverse crease and radial side of the proximal transverse crease.

Latent Print

An impression of the friction ridge skin recorded under accidental or uncontrolled circumstances. For this document, “latent print” also refers to a patent print, plastic print or inked prints on documents.

Lift

An adhesive or other medium used to transfer and retain a friction ridge impression from a substrate.

Live Scan

Electronic recording of friction ridges.

Loop

A pattern type in which one or more friction ridges enter upon one side, recurve, touch or pass an imaginary line between delta and core and flow out, or tend to flow out, on the same side the friction ridges entered.

Lower joint (of the finger)

The hinged area that separates segments of the finger.

Major case prints

A recording of all friction ridge detail appearing on the palmar sides of the hands. This includes the extreme sides of the palms, joints, tips, and sides of the fingers (also known as complete friction ridge exemplars).

Matrix

The substance that is deposited or removed by the friction ridge skin when making an impression.

Minutiae

The point where a friction ridge begins, terminates, or splits into two or more ridges.

NGI

The acronym for Next Generation Identification which is the FBI's AFIS system; the updated version of IAFIS.

No match

A negative result for a database search; it does not mean that no matching print exists in the database. This is different from a source exclusion.

Not conducive

Prints could be developed on an item; however, it is not likely (e.g. pens, pad locks, lug nuts, etc.)

Not suitable

Item is unable to be processed as prints would not develop on the substrate (e.g. fabric)

OBIS

The acronym for Ohio Biometric Identification System - a system used and maintained by the state of Ohio for the storage, retrieval and matching of finger and palm print records.

Observed data

Any demonstrable information observed within an impression that an examiner relies upon to reach a decision, conclusion or opinion. This has historcally been expressed as “features” or “minutiae,” but the use of the broader term “observed data” is inclusive of other types of data that may be considered beyond minutiae, such as quality, scars, creases, edge shapes, pore structure, and other friction ridge features.

Palmprint

An impression of the friction ridges of all or any part of the palmar surface of the hand.

Patent print

Friction ridge impression of unknown origin, visible without development, a type of latent print.

Pattern force area

A region of friction ridge skin in which minutiae of a particular type are forced to form due to the flow of the ridges.

Pattern type

Fundamental shape of the ridge flow: arch, loop, whorl.

Plastic print

Friction ridge impression of unknown origin that is impressed in a soft substrate to create a three-dimensional impression, a type of latent print.

Pores

Small openings in the skin through which perspiration is released.

Preliminary examination

An abbreviated examination of evidence in which all of the ridge detail present on an item was not analyzed for sufficiency or the processing of the item has been truncated. This may be utilized once a probative association has been made in the case.

Probability

_____ is an expression of the chance that a particular event occurs. For the purposes of this manual, probability is subjective - the degree of belief or confidence placed in the occurrence of an event by the professional judgement of an individual based on the available evidence.

Quality

The clarity of information contained within a friction ridge impression.

Quantity

The amount of information contained within a friction ridge impression.

Rarity (of a feature type)

The frequency that a type of feature is encountered in a population (its prevalence), either in isolation or in conjunction with other information about its local context.

Reagent

Substance used in a chemical reaction to detect, examine, measure, or produce other substances.

Ridge flow

The direction of the friction ridges. May lack a classifiable pattern.

Ridge path

The course of a single friction ridge.

Simultaneous impression

Two or more friction ridge impressions from the same hand or foot deposited concurrently.

Source

The individual who deposited a friction ridge impression(s).

Source exclusion

The conclusion that the observed data provides extremely strong support for the proposition that the evidence originated from a different source and the likelihood for the proposition that the evidence arose from the same source is so remote as to be considered a practical impossibility; or the evidence exhibits fundamentally different characteristics. This may also be referred to as exclusion.

Source identification

The conclusion that the observed data provides extremely strong support for the proposition that the evidence originated form the same source and the likelihood for the proposition that the evidence arose from a different source is so remote as to be considered a practical impossibility. This may also be referred to as identification.

Spatial relationship

Proximity of characteristics to each other.

Stock solution

Concentrated solution diluted to prepare a working solution.

Substrate

The surface upon which a friction ridge impression is deposited.

Sufficient (Sufficiency)

The determination that there is adequate data (quantity and quality of detail) in a friction ridge impression for some further process such as: retention in the case, further analysis by a forensic scientist, comparison with exemplar prints, or searching in AFIS.

Support for Different Source

The conclusion that the observed data provides more support for the proposition that the evidence originated from different sources rather than the same source; however, there is insufficient support for a Source Exclusion. The degree of support may range from limited to strong or similar descriptors of the degree of support. Any use of this conclusion shall include a statement of the factor(s) limiting a stronger conclusion.

Support for Same Source

The conclusion that the observed data provide more support for the proposition that the evidence originated from the same source rather than different sources; however, there is insufficient support for a Source Identification. The degree of support may range from limited to strong or similar descriptors of the degree of support. Any use of this conclusion shall include a statement of the factor(s) limiting a stronger conclusion.

Target group

A set of friction ridge features selected as a starting point during comparison.

Thenar

The radial side of the palm circumscribed by the thenar crease.

Tolerance

A means of expressing the variation that is allowable in two impressions originating from the same source due to the elasticity of the skin and differences in deposition and lateral pressure, twist, substrate, matrix, development medium, environmental factors, or post deposition damage.

Utility

The usefulness of an impression for a further step in the examination process, such as comparison or database entry.

Verification

The independent check of a conclusion by another qualified analyst.

Whorl

A fingerprint pattern type that consists of one or more friction ridges that make, or tends to make, a complete circuit, with at least two deltas.

Working solution

Solution at the proper dilution for processing.

Writer's palm

The ulnar edge ("blade") of the hypothenar and interdigital region of the palm that typically rests on a surface when a person is writing by hand.