Chapter 3 Vocabulary Study Guide for Crime Scene Investigation

Contracting or Expanding Spiral Search

A method of searching a crime scene where investigators walk in a spiral path either inward or outward from a central point, useful in areas without physical boundaries.

Crime Scene Photography

The process of taking photos of the scene, evidence, and surroundings using proper lighting, angles, and scales to preserve visual records

Cross-Projection Sketch

A sketch that shows multiple surfaces (like floor and walls) flattened into a single view to show the location of evidence more clearly.

Depth of Field

In photography, this refers to how much of the scene is in focus from front to back. A greater depth keeps more of the image sharp.

Druggist Fold

A method of packaging small trace evidence by folding paper into an envelope that keeps contents secure without tape or staples

F-Stop

A camera setting that controls how much light enters the lens. Affects exposure and depth of field.

Line or Strip Search

A search method where investigators walk in straight lines across the scene, best for large, open areas.

Notes

Written observations by the investigator that document times, locations, descriptions, and steps taken during the scene investigation

Sketches

Drawings made at the scene to show layout and location of evidence. Includes measurements, labels, and a legend

Videography

The use of video to document the crime scene in real time, often used for walkthroughs before evidence is moved.

Zone or Quadrant Search

Dividing the scene into smaller sections and assigning each to a different investigator. Good for indoor or cluttered spaces.

Daubert Evidence Rule

A legal rule that says expert testimony must be based on scientifically valid reasoning and methods

Deposit

Material left behind during contact, such as a blood drop or a fiber transfer

Exclusion

Determining that a piece of evidence does not match or relate to a known source

Expert Witness

A person qualified by knowledge, skill, or experience to give opinions in court that help the judge or jury understand the evidence

Frye Evidence Rule

An older rule that requires scientific evidence to be generally accepted by the relevant scientific community

Imprint

A type of evidence left behind by contact, such as a shoe print or fingerprint, on a hard surface.

Indentation

A mark made by pressure but without movement, like a bite mark or tire impression in mud

Known (K)

Samples of evidence from a known source, like the suspect's hair or a control substance used for comparison

Locard's Exchange Principle

The idea that whenever two things come into contact, there is always a transfer of material

Probable Cause

A legal standard meaning there's enough reason to believe a person committed a crime, used to justify searches and arrests.

Questioned (Q)

Evidence from an unknown source, such as an unidentified fingerprint or substance, that will be compared to known samples

Striation

Marks or scratches made by movement, like the grooves left on a bullet fired through a barrel

Trier of Fact

The person or group (judge or jury) who decides what the facts are in a case and makes the final decision.