Crime Scene Basics
Why is it important to restrict access and establish a perimeter at a crime scene?
To maintain the integrity of the scene and preserve evidence.
What is the main purpose of a polygraph test in a forensic investigation?
To measure physiological responses that may indicate deception.
What is the difference between presumptive and confirmatory blood tests?
Presumptive suggests a sample may be blood; confirmatory verifies it.
What is the main purpose of an autopsy?
To uncover clues about how and why a person died.
What are the three types of time of death?
Legal, Estimated, and Physiological.
What elements must be included in a crime scene sketch?
A key, legend, and accurate scale.
Which physiological responses are measured in a polygraph?
Heart rate, blood pressure, respiration rate, and skin conductivity.
DOUBLE JEOPARDY - What correctly matches each blood component with its function?
- Plasma
- Erythrocytes
-Leukocytes
- Plasma
Plasma – carries nutrients and proteins; RBCs – transport oxygen; WBCs – fight infection; Platelets – form clots.
Who performs an autopsy?
A coroner or medical examiner.
What correctly describes livor, algor, and rigor mortis?
Livor – blood settling; Algor – body cooling; Rigor – muscle stiffening.
DOUBLE JEOPARDY: Which search methods are most appropriate for indoor crime scenes like Anna Garcia’s?
Link and Zone methods.
DOUBLE JEOPARDY: What does skin conductivity refer to?
The amount of sweat that affects how well skin conducts electricity.
What is the main function of hemoglobin?
To transport oxygen using iron in red blood cells.
DOUBLE JEOPARDY: Match each autopsy term correctly.
Cause
Mechanism
Manner
Cause – specific injury/disease; Mechanism – physiological reason; Manner – circumstances of death.
In forensic entomology, what is an instar?
The developmental stage between molts of a larva.
What is the purpose of identifying a point of origin in a sketch?
It serves as a consistent reference point for all measurements.
Why is the experimental design process called iterative?
Because experiments repeat to verify and refine results.
A person’s plasma contains anti-A antibodies but not anti-B antibodies. What is their blood type?
Type B.
Which is an example of manner of death?
Homicide.
Which statement best describes the difference between a toxin and a toxicant?
Toxins are natural; toxicants are man-made.
What traits are most valuable for a biomedical scientist investigating a death?
Critical thinking, ethical behavior, and persistence.
DOUBLE JEOPARDY: What are the independent and dependent variable in a polygraph experiment?
Truth vs lie and The physiological changes being measured.
Match each DNA process with its purpose:
Extraction
PCR
Restriction
Gel electrophoresis
Extraction – removes DNA; PCR – copies DNA; Restriction – cuts DNA; Gel electrophoresis – separates fragments by size.
Which correctly matches body systems with their main functions?
Endocrine
Reproductive
Skeletal
Endocrine – glands releasing hormones; Reproductive – produces gametes; Skeletal – supports and protects body.
DOUBLE JEOPARDY: Which condition is associated with an enlarged heart and can lead to lethal arrhythmias?
Congestive Heart Failure.