Review Exam 1 - Forensic Science (Chapters 1-6)

Vocabulary flashcards covering key concepts from chapters 1–6 of the forensic science notes.

Forensic science

The application of science to criminal and civil investigations, including the collection, analysis, and interpretation of physical evidence for legal purposes.

Forensic science as a field

Not a standalone branch of science; it is the practical application of scientific methods to legal problems.

History of forensic science

Overview of how forensic science developed and the contributions of key individuals to its methods and practices.

Locard's Exchange Principle

The concept that any contact between a person and a scene results in an exchange of materials; every contact leaves a trace.

Oldest crime lab location

Lyon, France—the site of Edmond Locard's early laboratory established around 1910.

FBI's significance to forensic science

National coordination of standards, training, and laboratory services, plus databases (e.g., AFIS, CODIS) that advance forensic science nationwide.

Types of crime labs

Local/municipal, state, and federal laboratories that serve different jurisdictions and functions.

Determinants of crime lab size

Case load, funding, scope of services, and complexity of cases.

Lab units

Specialized sections within a crime lab (e.g., Biology/DNA, Firearms, Trace Evidence, Chemistry/Drug, Latent Prints, Digital/Computer, Documents).

Biology/DNA Unit

Analyzes biological samples (blood, semen, saliva) to obtain DNA profiles.

Firearms/Toolmarks Unit

Examines firearms, discharged ammunition, and tool marks to link elements to a suspect or weapon.

Chemistry/Drug Unit

Analyzes controlled substances and chemical evidence for identity and purity.

Trace Evidence Unit

Handles small evidence items such as fibers, hairs, glass, soil, and paint and assesses their connections.

Latent Prints Unit

Develops, analyzes, and compares latent (invisible) fingerprints recovered from evidence.

Documentation/Questioned Documents Unit

Examines documents, handwriting, and related marks.

Digital/Computer Unit

Analyzes digital evidence from computers, phones, and other electronic devices.

First officer at scene

Secures the area, provides aid as needed, detains witnesses, and prevents evidence contamination.

Lead investigator responsibilities

Oversees scene security, coordinates documentation and evidence collection, and leads the investigative process.

Crime scene documentation methods

Notes, sketches, photographs, and video—used to preserve a permanent record and support analysis and court proceedings.

Clothing collected from suspect

Suspect's clothing, removed and packaged to preserve trace evidence and prevent contamination.

Evidence collected from victim

Victim's clothing, personal items, and trace materials collected to establish identity and scene connections.

Handling trace evidence

Use proper collection, packaging, and handling to prevent contamination and maintain integrity.

Tools and packaging carried by evidence collectors

Forceps, swabs, scissors, tape, bags, labels, markers—used to collect and properly package evidence.

Chain of custody

The documented, unbroken sequence of custody transfers that preserves evidence integrity from collection to court.

Marking physical evidence

Case number, item number, description, date, and initials placed on packaging to identify and track evidence.

Standard vs Reference samples

Known-origin samples used for comparison with evidence; standards and references serve to verify results and identify sources.

Common types of physical evidence

Biological, chemical, and physical items such as DNA, blood, hair, fibers, glass, soil, and toolmarks.

Individual characteristics

Features that are unique to a source (e.g., DNA profile, unique fingerprint features, distinctive tool marks).

Class characteristics

Features shared by a group or source type (e.g., blood type, fiber type, glass type).

Significance of individual vs class evidence

Individual evidence can link to a single source; class evidence narrows possibilities to groups or sources.

Types of fingerprint evidence (categories)

Visible, Plastic, and Latent fingerprints—distinct forms of fingerprint evidence.

Visible fingerprints

Prints visible to the eye due to residue (e.g., ink, blood).

Plastic fingerprints

Three-dimensional impressions left in soft materials like clay or soap.

Latent fingerprints

Invisible fingerprints requiring development methods (chemical or physical) to be seen.

AFIS

Automated Fingerprint Identification System; digital system for storing and searching fingerprints.

Latent fingerprint development on porous surfaces

Ninhydrin and physical developer are common methods used on porous materials like paper.

Latent fingerprint development on nonporous surfaces

Cyanoacrylate fuming (superglue), powder dusting, and iodine fuming enhance latent prints on nonporous items.

Preserving developed latent fingerprints

Photograph, lift, and properly package; protect from moisture and smudging; store appropriately.

Fingerprint individuality and Henry number

Fingerprints can be individualized; Henry number is a classification method used to organize prints, not identification.

Obtaining a Henry number

Henry Classification System assigns numbers based on fingerprint patterns to aid searching.

Henry number is not individualized data

Used for classification and narrowing the suspect pool, not indicating a single person’s identity.

Additional prints linking to a crime scene

Palm prints and footwear/shoe prints, among others, can link a person to a crime scene.

AFIS database contents

Digital database containing fingerprint records and comparisons; used to identify matching fingerprints.

Live Scans vs Dead Scans

Live scans capture prints from living individuals; dead scans refer to latent or postmortem prints and prints recovered from evidence.