Identification 3 Flashcards
(21 cards)
What are four factors that could result in a fingerprint lift showing distortion?
- Matrix (residue left behind)
- Substrate (surface)
- Direction of touch
- Pressure of the touch
These factors contribute to the differences in appearance of fingerprints due to the conditions during deposition.
What is the concept of ‘tolerance’ in relation to observable differences between a latent print and a fingerprint sample?
Tolerance refers to the acceptable limits of differences in appearance due to various types of distortion
It is based on professional knowledge and experience, with some differences being easily explainable.
When considering substrate distortion, what are three types of substrate that may influence the appearance of the latent print?
- Porous
- Non-porous
- Semi-porous
Each type of substrate can affect how a fingerprint is transferred and how it appears.
What features are likely to be observed in a latent print on porous substrates?
Features may include clearer ridge detail due to absorption by the substrate
Porous surfaces can retain moisture and residues that enhance print visibility.
What features may be observed in wet prints with reference to matrix distortion?
- Smudging of ridges
- Loss of detail
- Blurring of patterns
Wet conditions can alter the appearance of the fingerprint significantly.
What features may be observed with fingerprints made in blood or paint due to matrix distortion?
- Viscosity affecting ridge clarity
- Possible color saturation
- Altered ridge patterns
The medium can impact how the print is deposited and its subsequent development.
What are the characteristics associated with powder as a development medium?
- Abrasive
- Collects in pores
- Tends to fill in third-level detail
These characteristics can obscure fine details of the fingerprint.
What are the characteristics associated with ninhydrin as a development medium?
- Reacts with amino acids
- Can appear spotty
Ninhydrin enhances ridge detail but may not provide a uniform appearance.
What are the characteristics associated with iodine fuming as a development medium?
- Non-abrasive
- Absorbs into matrix
- Shows third-level detail clearly
Iodine fuming is effective for developing latent prints without damaging them.
What are the characteristics associated with cyanoacrylate as a development medium?
- Polymerizes with the matrix
- Can create a ‘spaghetti-like’ appearance
- May leave a ‘flakier’ appearance
Cyanoacrylate is often used for its strong bonding capabilities with residues.
What is the difference between deposition pressure and pressure distortion?
- Deposition pressure: Vertical weight on ridges
- Pressure distortion: Lateral or horizontal pressure affecting ridge appearance
Understanding these distinctions is crucial for analyzing print quality.
What are six observable ‘red flag’ indicators of distortion in a latent fingerprint?
- Ridge disturbances
- Lines through pattern area
- Misaligned ridges
- Extra thick ridges
- Crossovers / double taps
- Lack of harmony in distortions
These indicators signal potential issues in the fingerprint analysis process.
Fill in the blank: ‘To distort’ is defined as __________.
[to modify so to produce an unfaithful reproduction; to change or misrepresent; to change the usual or normal shape, form, or appearance.]
This definition helps in understanding the nature of distortions in fingerprints.
What does the term ‘anatomical aspects’ refer to in the context of fingerprint distortion?
It refers to variations in how fingers contact surfaces, including overlaps and the natural sequence of digits
These variations can create unique impressions that differ from expected patterns.
What influences can affect the substrate type in fingerprint analysis?
- Surface type (porous, non-porous)
- Shape (flat, rough)
- Condition (wet, dirty)
These factors can significantly impact the quality and clarity of fingerprint impressions.
How does subjectivity factor into the ACE-V process?
Subjectivity is an inextricable part of the ACE-V process, affecting outcomes at every step
What is the concept of bias?
Bias distorts the way we perceive and evaluate information
What is cognitive bias?
The tendency to make decisions or take action in an illogical way
What is confirmation bias?
The tendency to look for information that supports existing beliefs and reject contrary data
What is contextual bias?
Occurs when other evidence influences the analysis of specific evidence, prompting biased decisions
How can you self-manage to avoid bias?
Keep an open mind, be impartial, never assume, examine everything as if it were a blank script
