1.1 - Investigating the Scene

Link Method

Crime scene search method with no set pattern; uses logical links to connect crime activity and evidence.

Line Method

Investigates a large outdoor area in straight lines or strips.

Grid Method

Two groups search a large outdoor area in lines, with one group searching in one direction and the other group in the opposite direction.

Zone Method

A crime scene search method where team members are assigned specific sections in small indoor areas.

Spiral Method

Crime scene search method starting from a critical point and spiraling outwards or inwards.

Wheel/Ray Method

Search method that involves moving outward from a critical point in a circular fashion.

Independent Variable

The variable that is manipulated in an experiment, such as the intensity of exercise.

Dependent Variable

The measurable variable in an experiment, such as heart rate.

Control Variable

Variables that are kept the same throughout an experiment to ensure valid results.

Cuticle

The outermost layer of a hair, which helps protect the inner layers.

Cortex

The middle layer of hair, containing pigment, density, and size indicators.

Medulla

The central core of a hair that adds volume and texture.

Arch fingerprint

A hair pattern where the ridges slope upward.

Tented arch fingerprint

A variation of the arch with a dramatic slope.

Loop fingerprint

A fingerprint pattern where ridges curve back on themselves.

Whorl

A fingerprint pattern that is circular or spiral.

Plasma

The liquid portion of blood that carries nutrients and proteins throughout the body.

Erythrocyte

Red blood cells that carry oxygen to the lungs and body.

Leukocyte

White blood cells that fight infection.

Thrombocyte

Platelets that help stop bleeding by clotting.

Hemoglobin

A protein in red blood cells that binds and carries oxygen.

Hematocrit

Percentage of erythrocytes in blood; low levels can indicate anemia.

Agglutination

The clumping of erythrocytes.

Transfer Blood Spatter

Smear, trail, or smudge created by a handprint or finger contact with blood.

Spatter Blood

Blood traveling through the air before landing.

Falling Droplet Blood Spatter

Blood dropped directly from above, creating a circular stain.

Radical Spatter

Blood spatter resulting from a large impact and high speed.

DNA

A negatively charged structure found in all living things, forming a double helix and housed in the nucleus.

Amino Acid

The building block of proteins and DNA.

Ribosome

Cell structure that assembles proteins.

Gene

A set of instructions for building proteins.

Chromosome

Tightly coiled packages of DNA.

Histone

Proteins around which DNA strands wrap.

Gamete

Sperm or egg cell.

DNA Extraction

The process of breaking open cells to find DNA within the nucleus.

Restriction Enzymes

Molecular scissors that cut DNA at specific recognition sites.

Blunt Ends

DNA ends created when restriction enzymes cut straight through recognition sites.

Sticky Ends

DNA ends created by jagged cuts made by restriction enzymes.

DNA Fragments

Small pieces of DNA resulting from restriction enzyme digestion.

Gel Electrophoresis

A technique that separates and analyzes digested DNA fragments by size.

Sources of DNA Extraction

Leukocytes, bones, hair, preserved body parts, clothing/fiber, saliva/body fluids.

Non-sources of DNA extraction

Erythrocytes do not contain a nucleus and, therefore, do not have DNA.

experimental design step 1

Identify the question

experimental design step 2

make a prediction

experimental design step 3

design an experiment

experimental design step 4

conduct experiment

experimental design step 5

analyze data

experimental design step 6

communicate findings

conversion factor

desired unit/given unit