Unit 1 forensic science and observation; Crime scene investigation and evidence collection

Analytical Skill

The ability to examine data and circumstances, enabling forensic scientists to derive conclusions based on evidence.

Deductive Reasoning

A process of logical reasoning where conclusions follow from established facts or premises.

Eyewitness

A person who sees an event, particularly a crime, which can provide firsthand testimony in investigations.

Fact

A statement or assertion that can be objectively verified as true.

Forensic Science

The application of scientific methods to aid in resolving legal matters through examination and analysis of evidence.

Hypothesis

A proposed explanation made on the basis of limited evidence as a starting point for further investigation.

Logical

Pertaining to clear, sound reasoning and the principles of valid inference.

Observation

The act of gathering information through the senses, often occurring subconsciously.

Opinion

A subjective statement that reflects personal beliefs or interpretations, which may differ from fact.

Perception

The interpretation of sensory input which can be influenced by preconceived notions or biases.

Purpose of Forensic Science

Applying scientific methods for investigating crimes and resolving legal matters through analysis and interpretation of evidence.

Role and Responsibilities of a Forensic Scientist

Collection, analysis, interpretation of physical evidence, and effective communication of results, potentially providing expert testimony in court.

Observation vs. Perception

Observation is collecting data using senses; perception involves interpreting that data, which can lead to inaccuracies.

Fact vs. Opinion in Eyewitness Testimony

Fact is objectively verified; opinion reflects personal views, leading to potential misinterpretation in testimonies.

Improving Observation Skills

Techniques include surveying surroundings systematically and documenting findings thoroughly.

Effective Eyewitness Interview Techniques

Separate witnesses immediately, avoid leading questions, and check for consistent responses signaling truthfulness.

Chain of Custody

The process of maintaining and documenting the handling of evidence from collection to court presentation.

Circumstantial Evidence

Evidence suggesting a fact but not directly proving it, requiring inference.

Class Evidence

Evidence sharing common characteristics but lacking unique elements linking it to a specific individual.

Crime-Scene Investigation

The systematic process of collecting, documenting, and analyzing evidence from a crime scene.

Datum Point

A reference point in mapping a crime scene used to triangulate evidence locations.

Direct Evidence

Links a suspect directly to a crime through firsthand observation or evidence.

First Responder

The first officer or emergency services member at a crime scene, responsible for securing the area.

Individual Evidence

Evidence that can be uniquely traced back to a specific source, such as DNA.

Paper Bindle

A packaging method made of paper to secure evidence and prevent contamination.

Primary Crime Scene

The location where the crime occurred.

Reliable Evidence

Evidence that is trustworthy based on scientific validation.

Secondary Crime Scene

Any location other than the primary crime scene where related evidence may be found.

Subdatum Point

A secondary reference point that helps in mapping elements of a crime scene.

Trace Evidence

Small materials transferred during a crime that provide crucial links.

Triangulation

A method of locating evidence using two fixed points for spatial reference.

Valid Evidence

Evidence that meets legal standards and can be admitted in court based on reliability and relevance.

Goals of Crime Scene Investigation

Accurately reconstruct events of a crime through relevant evidence.

Police Officers

Ensure scene safety and direct traffic.

Crime Scene Investigators (CSI)

Document and collect evidence.

District Attorneys

Evaluate evidence for prosecution needs.

Medical Examiners

Determine cause of death.

Detectives

Collect witness statements and search for evidence.

Lab Technicians

Analyze physical evidence

Locard’s Principle of Exchange

Individuals leave traces in their environment; foundational for trace evidence analysis.

Types of Evidence

Direct evidence provides proof; circumstantial evidence implies conclusions based on inference.

Step 1

Securing the Scene

Step 2

Separating Witnesses

Step 3

Scanning the Scene

Step 4

Seeing the Scene

Step 5

Sketching the Scene

Step 6

Searching for Evidence

Step 7

Securing and Collecting Evidence

Securing a Crime Scene

Ensure safety and restrict access to authorized personnel to maintain integrity.

Documenting a Crime Scene

Use photographs, sketches, and notes for accurate detail capture.

Collecting and Packaging Trace Evidence

Use appropriate techniques like packaging, seal, and labeling the evidence.

Analyzing Evidence

evidence analysis, crime scene reconstruction and legal processes

Staged Crime Scene Identification

Identify inconsistencies in evidence, witness statements, and motives suggesting falsifying.

Advances in Technology

Includes digital forensics, surveillance systems, drones for aerial documentation, and 3D modeling.