Forensic Science Bailey Final

Mathieu Orfila

Known as the 'Father of Toxicology.'

Alphonse Bertillon

Created Anthropometry (a system of identifying bodies through measurements).

Francis Galton

Developed the first scientific system for classifying fingerprints.

Leon Lattes

Created a procedure to determine blood type from a dried blood stain.

Calvin Goddard

Refined the use of the comparison microscope to match bullets to guns.

Albert S. Osborn

Established the fundamental principles of document examination.

Walter C. McCrone

Pioneered the use of microscopes to solve forensic mysteries.

Hans Gross

Wrote the book on applying different sciences to criminal investigations.

Edmond Locard

Developed the 'Exchange Principle' (every contact leaves a trace).

Locard's Exchange Principle

'Every contact leaves a trace' (whenever two objects touch, a transfer of material occurs).

Observation

A careful, sensory gathering of information about a scene or evidence.

Are observations always reliable?

No, human perception is subjective, limited, and prone to error.

What influences observations?

Biases, expectations, fatigue, environment, distractions, or being watched.

Role of Police Officers

To secure the scene and keep unauthorized people out.

Role of CSI Investigators

To collect evidence through photos, dusting for prints, and obtaining physical evidence.

Role of Detectives

To solve the crime by interviewing witnesses and using evidence to find suspects.

Role of Medical Examiners

To examine the body to determine the cause and time of death.

1. Secure the scene

First officer ensures safety and sets up physical barriers to prevent contamination.

2. Separate the witnesses

Keep witnesses apart so they do not talk and influence each other's stories.

3. Scan the scene

A quick walkthrough to determine where the crime happened.

4. See the scene

The photography unit takes photos of all evidence before it is touched.

5. Sketch the scene

Investigator draws the scene, including the body and fixed points.

6. Search for evidence

Systematic search to find all physical evidence at the scene.

7. Secure and Collect

Evidence is sealed, labeled, and a Chain of Custody is started.

Evidence Log

A detailed, written record used to track evidence collected at a scene.

Chain of Custody

A record of an item's handling from collection to court to prove integrity.

Class Evidence

Evidence that points to a group of people/things (has common traits).

Individual Evidence

Evidence that points to a single person (is unique and has imperfections).

Biological Evidence Storage

Should be placed in a paper bag when dry to prevent mold.

Liquid Evidence Storage

Should be placed in a leak-proof bottle and then a second container.

Cuticle

The outermost layer of hair; dead cells that protect the inner layers.

Cortex

Middle layer of hair; provides strength, elasticity, and texture (contains pigment).

Medulla

The innermost core of the hair; may provide structural support.

Human Medulla Patterns

Continuous, Interrupted, Fragmented, or Absent.

Human vs. Animal Hair

They differ in growth patterns, internal structure, and pigmentation.

Hair as Evidence

Usually Class Evidence (unless the root is attached for DNA analysis).

Fiber as Evidence

Trace Evidence; small and easily transferred.

Destructive Fiber Test

The Burning Test (requires burning the fiber to observe smell and ash).

Cross-transfer of fibers

Used to link suspects to victims or specific locations.

Patent Prints

Visible prints made by blood, ink, or dirt.

Latent Prints

Invisible prints left by oils/sweat; require powder or chemicals to see.

Plastic Prints

3D impressions left in soft materials like wax, soap, or dust.

Whorl

Circular patterns (spirals/ovals) with at least two deltas.

Arch

Ridges enter one side and exit the other with a rise in the center; no deltas.

Loop

Ridges enter and exit from the same side; has one delta.

Best Surface for Collection

Smooth, quiet (low traffic) surfaces are easier because there is less debris/interference.