Palmprint
An impression of the friction ridges of all or any part of the palmar surface of the hand.
Pattern classification
Sub-division of pattern type, defined by classification systems such as Henry or National Crime Information Center (NCIC) classifications.
Pattern type
Fundamental pattern of the ridge flow: arch, loop, whorl. Arches are subdivided into plain and tented arches; loops are subdivided into radial and ulnar loops; whorls are subdivided into plain whorls, double loops, pocket loops, and accidental whorls.
Phalanx/Phalange
1. A bone of the finger or toe.
2. Sometimes used to refer to a segment of a finger.
Poroscopy
A study of the size, shape, and arrangement of pores.
Positive predictive value (PPV)
The proportion of individualization decisions that are correct.
Primary image
The first recording of an image onto media.
Proficiency
The ongoing demonstration of competency.
Quality
The clarity of information contained within a friction ridge impression.
Quantity
The amount of information contained within a friction ridge impression.
Ridge flow
1. The direction of one or more friction ridges.
2. A component of Level 1 detail.
Ridge path
1. The course of a single friction ridge.
2. A component of Level 2 detail.
Ridge unit
See friction ridge unit. Friction ridge unit: A single section of ridge containing one pore.
Segment (of the finger)
The proximal, medial, or distal section of the finger.
Short ridge
A single friction ridge beginning, traveling a short distance, and then ending.
Simultaneous impression
Two or more friction ridge impressions from the same hand or foot deposited concurrently.
Source
An area of friction ridge skin from an individual from which an impression originated.
Spur
A bifurcation with one short friction ridge branching off a longer friction ridge.
Stand-alone
A segment of a simultaneous impression that has sufficient information to arrive at a conclusion of individualization independent of other impressions within the aggregate.
Substrate
The surface upon which a friction ridge impression is deposited.
Sufficiency
The product of the quality and quantity of the objective data under observation (e.g., friction ridge, crease, and scar features).
Sufficient
The determination that there is sufficiency in a comparison to reach a conclusion at the evaluation stage.
Suitable
The determination that there is sufficiency in an impression to be of value for further analysis or comparison.
Target group
A distinctive group of ridge features (and their relationships) that can be recognized.
Technical review
Review of notes, documents, and other data that forms the basis for a scientific conclusion (see ASCLD-LAB 2008 Manual).
Tenprint
1. A generic reference to examinations performed on intentionally recorded friction ridge impressions.
2. A controlled recording of an individual’s available fingers using ink, electronic imaging, or other medium.
Tolerance
The amount of variation in appearance of friction ridge features to be allowed during a comparison, should a corresponding print be made available.
Trifurcation
The point at which one friction ridge divides into three friction ridges.
Type lines
The two innermost friction ridges associated with a delta that parallel, diverge, and surround or tend to surround the pattern area.
Verification
The independent application of the ACE process as utilized by a subsequent examiner to either support or refute the conclusions of the original examiner; this may be conducted as blind verification. Verification may be followed by some level of review as specified by agency policy.
Whorl – accidental
1. A pattern type consisting of the combination of two different types of patterns (excluding the plain arch) with two or more deltas.
2. A pattern type that possesses some of the requirements for two or more different types of patterns.
3. A pattern type that conforms to none of the definitions of a pattern.
Whorl - central pocket loop
A pattern type that has two deltas and at least one friction ridge that makes, or tends to make, one complete circuit, which may be spiral, oval, circular, or any variant of a circle. An imaginary line drawn between the two deltas must not touch or cross any recurving friction ridges within the inner pattern area.
Whorl - double loop
A pattern type that consists of two separate loop formations with two separate and distinct sets of shoulders and two deltas.
Whorl – plain
A fingerprint pattern type that consists of one or more friction ridges that make, or tends to make, a complete circuit, with two deltas, between which, when an imaginary line is drawn, at least one recurving friction ridge within
the inner pattern area is cut or touched.