week 1 - forensic science

Definitions: Understanding terms is crucial in science, as they convey specific meanings. Forensics has evolved to mean the application of scientific knowledge in legal contexts.
Historical Development of Forensic Science: Discusses the evolution of forensic science from public discussions in ancient times to modern legal practices.

Forensics: Derived from Latin, originally meant public discussion. Evolved to encompass the application of scientific principles in law.
Science: The systematic study of the natural world, focused on observation, experimentation, and theory development. Inquiry about phenomena leads to hypotheses that are tested through experiments.
Forensic Science: The merger of scientific methodologies with legal frameworks to address legal and criminal investigations.

Basic Observations: The foundation of scientific inquiry.
Communication through Journals: Scientists share findings, validating observations for collective understanding.
Body of Knowledge: This validation builds a robust base of scientific inquiry.

Adversarial System: Legal proceedings where two parties present differing arguments for resolution.
Prosecution: The process involving the identification of crimes and suspects, varying by jurisdiction.
Integration of Science and Law: Not straightforward, with both domains needing to meet to form cohesive legal arguments.
- Admissibility: Essential in legal contexts regarding the acceptance of evidence in court.
- Based mostly on physical evidence collected at crime scenes, which can indicate criminal activity.

Direct Evidence: Eyewitness accounts or video showing the crime directly, requiring no inference.
Circumstantial Evidence: Requires inference and interpretation based on combinations of observed facts, potentially leading to conclusions that can be challenged.
Negative Evidence: Indicates a lack of expected occurrences that might imply involvement in a crime, e.g., a guard dog not barking during a burglary.

Criminal vs Civil Cases: Different legal outcomes and evidence standards.
- Criminal Cases: Evidence must prove beyond a reasonable doubt (at least 95% confidence).
- Civil Cases: Follows the preponderance of evidence (greater than 50% confidence).
Importance of Evidence: Distinguishing whether evidence identifies offenses or merely provides leads without strong conclusions.
Examples of Evidence: Fingerprints, eyewitness accounts, and physical traces can point towards individuals but must be corroborated by additional evidence.

Microscopy: Evolved into a key tool in forensic examinations, especially for trace evidence.
Photography: First introduced in 1591 using silver nitrate; evolved significantly over time.
Ultraviolet Rays: Discovered in 1804, allows for visualization of hidden writings.
Toxicology: Early key developments included compilation of known poisons; techniques have been developed for identifying them.
Ballistics: The science involving the behavior of firearms and ammunition.
Fingerprints: Originally for identification in financial transactions, evolved into a crime-solving tool.
Anthropometry: A technique that was eventually replaced by fingerprints for individual identification due to its unreliability.
DNA Profiling: Established in 1984 as a game-changer in forensic identification processes.

Contact Trace Theory: The principle that a perpetrator will leave behind and carry away evidence from a crime scene.
Types of Trace Evidence: Includes biological fluids (blood, semen), clothing fibers, hair, tools left behind, etc.
Statistical Analysis in Forensic Evidence: The application of statistics to evaluate evidence and prevent wrongful convictions.
- Causation vs Correlation: The difference between associative evidence and actual causative connections must be clarified.
Importance of Eyewitness Testimony: Documenting evidence from crime scenes which connects objects to their locations for further investigation.

Laboratory Work: Requires strict protocols for evidence collection, handling, and analysis.
- Types of Laboratories: Biological sciences, analytical services, and crime scene operations, each focused on specific aspects of forensic investigation.
Evidence Management Units: Where collected items are processed, cataloged, and stored safely for analysis.
Field Officers: Attend crime scenes to gather evidence; scientists usually work primarily in labs.

Fingerprints: Collection, analysis, and matching to databases.
Blood and DNA Analysis: Techniques for identifying suspects and determining involvement from biological evidence.
Drug Analysis: Identification of substances through various analytical techniques, including chromatography and mass spectrometry.
Explosives Handling: Techniques for identifying accelerants in arson investigations.

Educational Pathways: Ways to enter forensic science, either as field investigators or in laboratory positions, often needing interdisciplinary studies.
- Principles of forensic science apply to civil cases, insurance claims, and environmental forensics.
Statistical Validity: Importance of precise statistics in forensic evidence to avoid misinterpretations during legal proceedings.

The Role of Forensic Science: It combines scientific inquiry with legal frameworks to provide a structured approach to investigating crimes, aiding in the prosecution and defense through various evidences and analyses.