ACE-V Process Flashcards by Sharon Miyashita

What are the 4 premises of FR identification process?

Friction ridges develop in fetus and are definitive form before birth

Persistent throughout life- except scarring

Patterns and details in small areas are unique & not repeated

Overall FR patterns very within limits which allow for classification

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What is the philosophy of FR identification process?

Friction ridge identification is established through the agreement of friction ridge formations in sequence.

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What is the Quantitative/qualitative process?

High quality detail means low tolerance for dissimilarities and therefore a decrease in the quantity is required

Low quality detail means a high tolerance for dissimilarities and therefore an increase in the quantity is required

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What is the difference between dissimilarity and discrepancy?

Dissimilarities can be explained within reason

Discrepancies can NOT be explained

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What is the friction ridge identification process?

ACE-V

Analysis
Comparison
Evaluation
Verification

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Define Analysis

An objective process that evaluates an unknown impression to determine if there is sufficient quantity and quality to conduct a comparison.

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Should you document your analysis?

If so when should it be completed?

Yes

Complete prior to any comparison to any known impressions

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What are the seven factors of the analysis phase?

Anatomical factors 
Substrate 
Matrix 
Development medium
Deposition pressure
Lateral distortion (movement)
Clarity/Tolerance

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What do the anatomical factors to look at?

How was the handled

Digit determination

Not at not be able to determine either and digit determination is just a guess

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What should be noted about the substrate?

It is the surface in which the impression had been deposited

Make note of any contaminates/characteristics that may interfere with the impression and if it did or didn’t

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What should noted about the matrix?

Note what it is especially if not the most common material

Most common- sweat and sebaceous oils

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Define Development medium and what should be known about them
.

It is the what was used to make a fingerprint impression visible or to increase the contrast

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What are the signatures of powders?

Adhere to the matrix

Are abrasive

Powders can fill in some details

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What are the signatures of chemicals?

React with the components in the matrix

Some chemicals can be over processed

Ex- Ninhydrin reacts with amino acids

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Define deposition pressure

It is the amount of downward pressure when friction ridges come in contact with a substrate

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When describing deposition pressures what should be included?

What are the main descriptions?

Describe both the ridges and furrows

Light

Normal

Medium/moderate

Heavy

What is tonal reversal?

It is when excessive pressure was used to deposit the impression and the sweat it pushed into the furrows.

So the ridges change from light to dark and furrows go from light to dark.

Define lateral distortion and when it occurs

It is the movement of the finger after contact with the substrate

Can occur on initial contact
When contact is maintained with the substrate
Upon the finger leaving the substrate

Due to the flexibility of friction skin

What are the types of lateral distortion?

Streaking or dragging of matrix
Twisting 
Leaving the surface 
Shadowing 
Feathering

What are some red flags with lateral distortion?

Sudden differences in appearance of matrix or development medium
Lines running through friction ridge detail
Extra thick ridges
Shadow ridges
Crossovers
Angular joints
Similar shaped major ridge path deviations in close proximity
Lack of harmony in distortion
Misaligned ridges/ridge units

What are the two functions of clarity?

Dictates the level of detail available for comparison (level 1,2,3)

Dictates the level of tolerance for dissimilarities

What is level 1 detail?

Friction ridges

Flow of friction ridges

Can sometimes provide enough information to determine pattern

Can be used to exclude (if high level of distortion is present consider comparing level 2 detail before excluding)

What is level 2 detail?

Specific friction ridge paths and features (major ridge path deviations)

Can be used to exclude or identify

What is level 3 detail?

Consists of intricate shapes present within the friction ridges (edges,pores, alignment or misalignment of ridges)

Can add weight to an identification

Cannot be used as the basis for an exclusion

Define tolerance

The level of tolerance is based on the objective analysis of dissimilarities of an impression be viewing all 3 levels of detail and making a subjective assessment for the tolerance toward discrepancies.

How are comparisons conducted?

Side by side comparison Unknown on the left, known print on the right Visual ridge by ridge inspection determining if agreement based on similarity, sequence and spatial relationships Objective description of visual differences and agreement

What is done in the comparison process

Narrow down the search - digit determination can assist Observe overall configuration or pattern of FR Observer overall core to delta(s) distance Locate a target area Determine a starting point Ridge to ridge comparison in sequence of all available detail

What is th evaluation stage

Conclusion based upon analysis and comparison of FR Provide an explanation for differences when applicable Clear statement of opinion

Need to be able to answer what 2 questions each time you do a comparison

Is there agreement of friction ridge detail between the unknown and known? Is there sufficient agreement in the friction ridge detail to identify.

What is a consideration when evaluating the detail?

Look at the specificity (rarity) of the features seen. Most common features 1- ridge endings 2- bifurcations

What is pattern force?

It is the anticipated appearance of certain types of minutiae in specific parts of a pattern’s ridge flow; due to stresses placed on the developing friction ski in those locations.

What is the common pattern force for loops? Whorls? Deltas?

Common for ridge endings on the outflow Common to find a series of bifurcations below the core Short ridges are commonly found in and near the delta - b/c last area where FRs form

Is the evaluation objective or subjective?

ACE-V is subjective

What are the three possible conclusions in the ACE-V process?

Identification: donors are the same Exclusion: the donors are not the same Inconclusive: cannot identity or exclude (need to explain why)

What is the verification process?

Verification is the independent examination by another qualified examiner Verification of the methodology (theory) and the identification process (technique) to ascertain if they are sound (validating the science issues) Verifier should conduct own ACE

What are the three biases.

Cognitive: effect of perceptual or mental processes on the reliability and validity of ones observations and conclusions Contextual: the effect of information or outside influences on the evaluation or interpretation of data Confirmation: tendency to search fo data or interpret information in a manner that supports one’s preconceptions

How can we defend against bias arguments in court?

Some version of blind verification