Lecture 1: Brief Introduction

Question 1

What is Locard’s exchange principle?

Answer 1

• Every contact leaves a trace
• Physical materials are exchanged whenever contact occurs.

Question 2

Define qualitative analysis in the context of forensic science.

Answer 2

To determine the property or identity of a substance

An example would be identifying the poison in a sample.

Question 3

Define quantitative analysis in the context of forensic science.

Answer 3

To determine the amount or concentration of a substance in a sample

An example would be determining the concentration of poison in blood.

Question 4

What is the difference between accuracy and precision in analytical results?

Answer 4

• Accuracy: how close results are to the true value
• Precision: how reproducible measurements are

Both are critical for reliable forensic analysis.

Question 5

What are fingerprints used for in forensic science?

Answer 5

Personal identification

Two assumptions are: fingerprints remain unchanged throughout life, and no two fingerprints are identical.

Question 6

What historical text is considered the first to systematically describe crime scene investigation?

Answer 6

The Washing Away of Wrongs, written by Song Ci in 1247

Question 7

What scientific discovery in 1953 was significant for forensic science?

Answer 7

Discovery of the deoxyribonucleic acid (DNA) structure

This led to the use of DNA analysis for individual identification in 1984.

Question 8

What is the role of chromatography in forensic science?

Answer 8

It is one of the main methods of separating mixtures into individual components, based on their attraction to a stationary phase and a mobile phase.

This technique relies on different compounds being attracted to or repelled by other compounds.

Question 9

What are the main components of a crime scene investigation?

Answer 9

• Recovery of evidence from the crime scene
• Analysis of the recovered evidence
• Presentation of scientific test results in court

Question 10

In chromatography, what happens if a component is attracted only to the mobile phase?

Answer 10

It will move as fast as the mobile phase.

Question 11

In chromatography, what happens if a compound is attracted only to the stationary phase?

Answer 11

It will not move at all.

Question 12

What type of evidence is used in arson investigations?

Answer 12

Fire debris and accelerants.

Question 13

What types of evidence are analyzed in explosion investigations?

Answer 13

• Propellant
• Explosive formulations
• Pre- and post-blast samples and residue

Question 14

List some examples of materials analyzed in forensic evidence.

Answer 14

• Soil
• Glass
• Paint and ink
• Fibers
• Plastics
• Paper
• Bullets

Question 15

What is the focus of forensic toxicology?

Answer 15

Drug analysis.

Question 16

What types of samples are analyzed in forensic toxicology?

Answer 16

• Pills
• Drug powders
• Blood
• Urine
• Tissue
• Hair

Question 17

What does forensic analysis typically involve?

Answer 17

Analyzing physical evidence to support criminal investigations.

Question 18

In a case study, what evidence can be obtained from a victim inside a car?

Answer 18

• Fibers from the victim’s clothing
• Blood, hair, and skin cells

Question 19

What can tire tracks left by a vehicle indicate in a crime scene investigation?

Answer 19

The type of vehicle, which can help narrow down suspects.

Question 20

What can be used to identify a vehicle involved in a crime if found?

Answer 20

Small imperfections in the tire tread.