Physical Evidence Flashcards
What is testimonial evidence?
Evidence by lay or expert witness; witness needs to be ‘competent’ to testify. This involves statements or testimony given by witnesses, victims, or suspects. Witness accounts, confessions, and expert testimony fall under this category. Testimonial evidence can be powerful but is subjective and can be influenced by various factors.
What is physical evidence?
Physical objects supported by a chain of custody.This includes tangible items found at a crime scene that can be collected, preserved, and analyzed. Examples include weapons, clothing, fingerprints, fibers, hair, bodily fluids, and impressions (such as shoeprints or tire tracks).
What is documentary evidence?
Any written or printed material that can be used as evidence in a case such as wills, business records, memos, emails, etc.
What is demonstrative evidence?
Evidence created for trial – it helps illustrate testimony (e.g. animations, visual aids, diagrams, maps, photographs, etc.)
What is a lot of physical evidence considered?
Transfer evidence
What is transfer evidence?
The exchange of materials between two objects that occurs whenever two objects come into contact with one another.
How long can transfer evidence stay?
Transfer evidence, such as fibers, hairs, or other trace materials, can persist for varying lengths of time:
Fibers: Synthetic fibers, like nylon or polyester, can be quite resilient and may persist for extended periods, potentially years, especially if they’re not exposed to harsh environmental conditions. Natural fibers like cotton or wool might degrade more quickly.
Hairs: Hairs can remain intact for a long time if preserved well, such as in controlled environments or if protected from degradation factors like sunlight, moisture, or extreme temperatures.
Other Trace Materials: Other trace materials like soil, pollen, or paint chips can endure for extended periods, but their detectability might decrease over time due to environmental exposure or contamination.
What are the 3 major components of analysis of physical evidence?
- Identification
- Comparison
- Reconstruction
What is identification - analysis of physical evidence
The process of determining
a substance’s physical or
chemical identity with as
near absolute certainty as
existing analytical
techniques will permit. Sometimes to level of
manufacture. It is the question of “what is it?”
What is comparison - analysis of physical evidence
Comparison involves examining two or more samples to determine if they share common characteristics or if they are similar or dissimilar. Forensic analysts compare a questioned sample (evidence from a crime scene) with a known sample (standard/reference sample). This process aims to identify similarities or differences in physical characteristics, such as texture, colour, size, or microscopic details. Depends on determination of an item’s characteristics - Individual vs. class
What is reconstruction - analysis of physical evidence
Reconstruction involves piecing together the available evidence to create a cohesive and logical interpretation of events that occurred during a crime. Forensic reconstruction integrates various types of evidence to create a plausible sequence of events or circumstances. It may involve understanding the movement of individuals or objects, the sequence of actions, or the dynamics of an incident based on the physical evidence available.
What are individual characteristics?
characteristics that can be associated with a particular, unique source
Example: fingerprints, DNA profiles, and unique tool marks are individual characteristics. These traits are distinctive to a single source and are highly specific, allowing forensic experts to match them to a particular person or object.
What are class characteristics?
characteristics that can be associated only with a group and never with a single source.
Example: types of ammunition, shoe size and brand, and the type of fibers found in a piece of clothing are class characteristics. While they can suggest a common origin or group, they are not unique enough to identify a single source definitively.
What kinds vehicle investigations are there?
◦Routine minor crashes
◦ Intoxicated driving
◦ Major accidents with fatalities
◦ Hit and Run scenarios
What does airbag analysis allow us to do?
Helps us answer the questions:
◦Who was the driver?
◦Who was the passenger?
◦What happened at and just after the point of
impact?
