Physical Evidence, Forensic Law, and Crime Scene Investigation

Vocabulary flashcards covering physical evidence reliability, legal search warrant rules, standards of evidence admissibility (Frye, Daubert, Rule 702), legal exceptions, crime scene roles, the Seven S's, search patterns, and evidence packaging protocols.

Physical Evidence

Any tangible material or object relevant to a crime, generally more reliable than testimonial evidence because it can prove a crime occurred, corroborate or refute testimony, link a suspect to a victim/scene, and allow reconstruction of events.

Fourth Amendment

The constitutional amendment most relevant to forensics, requiring law enforcement to obtain a judge-signed and notarized search warrant before searching a home.

Plain Sight Doctrine

A legal rule allowing officers to seize evidence without a warrant requirement if the evidence is clearly visible in plain view.

Exclusionary Rule

A rule stating that evidence obtained illegally by police cannot be used in court, even if it is a key piece of evidence or risks exonerating the defendant.

Fruit of the Poisonous Tree Doctrine

A branch of the Exclusionary Rule stating that any evidence derived from illegally obtained primary evidence is inadmissible in court.

Frye Standard

A legal standard for admitting scientific evidence, requiring that the method be generally accepted and commonly used or trusted by experts within that scientific field.

Daubert Standard

A legal standard where the trial judge acts as the gatekeeper to determine if scientific evidence is relevant and reliable based on testability, peer review, scientific standards, and error rates.

Federal Rule of Evidence 702

The federal rule reflecting the Daubert approach, permitting expert testimony if the expert is qualified, the testimony assists the trier of fact, and it relies on sufficient, reliably applied facts or data.

Circumstantial Evidence

Evidence based on suggestion or inference rather than direct personal knowledge or observation.

Probative Value

The ability or degree of evidence to prove something material to a crime.

District Attorney

The legal officer on an investigation team who determines whether a search warrant is needed and provides legal guidance.

Medical Examiner

A medical professional called when a body is present to examine the victim and establish both the cause of death and manner of death.

Cause of Death

The specific injury or physical condition that directly caused a person to die, such as a gunshot wound.

Manner of Death

The broad legal category of death, classified as homicide, suicide, accident, natural, or undetermined.

Seven S's of Crime Scene Investigation

The seven sequential steps of crime scene processing: 1. Secure the scene, 2. Separate the witnesses, 3. Scan the scene, 4. See the scene, 5. Sketch the scene, 6. Search for evidence, and 7. Save / Collect evidence.

Memory Conformity

The phenomenon, also known as collusion, where witnesses discuss an incident and unintentionally alter or contaminate each other's recollections.

Overall Photograph

A crime scene photograph taken from a wide perspective to capture the entire scene and provide spatial orientation.

Mid-Range Photograph

A crime scene photograph showing evidence in relation to surrounding objects and fixed reference points.

Close-Up Photograph

A detailed photograph of specific evidence taken both with and without a measuring scale before the item is moved.

Triangulation Method

A crime scene sketching technique where an item of evidence is pinpointed by measuring distance to it from at least two fixed reference points.

Linear Search Pattern

A search technique where investigators walk in straight, parallel lanes approximately an arm's width apart; ideal for large, open outdoor areas.

Grid Search Pattern

A search technique consisting of two linear searches conducted perpendicular to each other, providing a thorough search for indoor or detailed scenes.

Spiral Search Pattern

A search pattern moving in a circular path either inward toward the center or outward from a central point, typically conducted by 1 or 2 searchers.

Zone Search Pattern

A search technique dividing a complex crime scene into smaller sectors or zones, useful for searching buildings, vehicles, or large areas with multiple searchers.

Biological Evidence Packaging

The packaging protocol requiring biological items to be fully air-dried and stored in breathable paper containers or envelopes rather than sealed plastic.