Physical Evidence Test Flashcards

Questions and Answers

What is the difference between class and individual evidence?

Class characteristics are not unique to a particular object but place the particular bit of evidence into a group of objects. Individual characteristics narrow down the evidence to a single, individual source.

What are examples of class versus individual evidence?

Hair (correct)

Blue denim (correct)

Fingerprints (correct)

White cotton (correct)

How is the crime scene reconstructed?

By developing a likely sequence of events using physical evidence and statements made by individuals.

What is the significance of physical evidence?

It helps narrow down possibilities of people or what happened and can also be used to trace to a witness or suspect. Signup and view all the answers

Why is evidence dried before packaging?

Everything needs to air dry before packaging to avoid smudging and potentially losing evidence. Signup and view all the answers

What is the Product Rule?

Turn percentages into a decimal and then multiply them all together, then by the population. Signup and view all the answers

What is a druggist fold?

A folded paper used to hold trace evidence. Signup and view all the answers

What type of evidence is found more often?

Class evidence. Signup and view all the answers

What types of evidence have databases? (Select all that apply)

DNA Databases Signup and view all the answers

All evidence needs an evidence label and a _____ of custody.

chain Signup and view all the answers

What is the importance of standards in evidence evaluation?

To ensure that the test you're doing is reacting with the evidence. Signup and view all the answers

Study Notes

Evidence Types

Class Evidence: Non-unique characteristics that place evidence into general categories; more common than individual evidence.
Individual Evidence: Unique characteristics that identify evidence down to a specific source, like fingerprints or specific paint layers.

Examples of Evidence

Class Evidence: White cotton fibers, blue denim.
Individual Evidence: Specific fingerprints, hair, or unique paint chips.

Crime Scene Reconstruction

Involves developing a probable sequence of events through physical evidence and eyewitness statements.
Sources of information include physical evidence, medical examiner reports, and detective notes.

Significance of Physical Evidence

Helps narrow down suspects and understand the sequence of events in a crime.
Can link a suspect to a witness or vice versa.

Evidence Packaging Protocol

Evidence must be air-dried before packaging to prevent smudging and loss of crucial details.

Product Rule Calculations

Convert percentages to decimals and multiply together; multiply by the relevant population for probability estimates.
Example: For a population of 350, calculate using 45%, 20%, and 3% multiplied together.

Druggist Fold (Paper Bindle)

A folded paper used for collecting trace evidence; steps include folding and securing with tape.
Important for preserving the integrity of small evidence samples.

Evidence Evaluation

Check if evidence is properly collected and packaged.
Verify the chain of custody and labeling for all evidence.

Frequent Evidence Types

Class evidence is encountered much more frequently in forensic investigations.

Databases for Evidence Types

Fingerprint Database: IAFIS (Integrated Automated Fingerprint Identification System).
DNA Database: CODIS (Combined DNA Index System).
Ballistics Databases: NIBIN (National Integrated Ballistics Network) and IBIS (Integrated Ballistics Identification System).
Vehicle Paint Database: PDQ (Forensic Automotive Paint Data Query).
Shoe Print Database: SICAR (Shoe print Image Capture and Retrieval).

Evidence Collection Methods

All evidence requires proper labeling and documentation of chain of custody.
Biological Samples: Techniques vary for liquid, dried blood, semen, and saliva.
Documents: Originals are essential, packaged separately to prevent damage.
Drugs: Various methods for plants, powders, and prescriptions; always enclosed in suitable containers.
Explosives: Handled by trained personnel; residues must be collected in appropriate containers.
Fibers/Hairs: Collected with tools and packaged securely.
Fingerprints: Collected using dust and tape methods.
Firearms: Must be unloaded; packaged separately and securely.
Glass: Packaged in protective containers or wrapped in cotton.
Impressions: Photographed first and can be made using dental clay.
Organic Samples: Collected with specific considerations for biohazard materials.

Importance of Standards in Evidence Evaluation

Standards ensure consistent reactions during testing, validating the evidence being examined.

Description

This quiz focuses on understanding the concepts of class and individual evidence in physical evidence analysis. It explores definitions, differences, and examples to deepen your comprehension of forensic evidence classification. Enhance your knowledge to prepare effectively for tests.