Fingerprinting Basics

Fingerprint Analysis

​​How are finger Prints Unique?

• Made up of ridges (raised lines) and valleys (spaces between)

• No two people have exactly the same fingerprints

• Stay the same throughout life unless scarred

Fun Fact: Koala Finger Prints

• Koalas have fingerprints similar to humans

• Even with powerful microscopes, they're hard to tell apart

• They're one of the few non-primates with fingerprints

• Scientists think this developed to help them grip tree branches

This is the science of fingerprints...

• ​Police collect "dactylograms" (fingerprints)

• Used to identify people

• Based on three main pattern types

• Used in crime-solving and identification

Dactyloscopy

Multiple Select

What are the 3 types of patterns a finger print can have?

• Arch

• Whorl

• Loop

• Divot

• Simplest pattern type

• Ridges enter one side and exit the other

• Two types:

• Plain arch (smooth curve)

• Tented arch (has a spike in middle)

• About 5% of people have arches

Type 1- Arches

• Most common pattern

• Has one delta (triangle shape)

• Ridges enter and exit on same side

• Two types:

• Ulnar loop (toward pinky)

• Radial loop (toward thumb)

• About 60% of people have loops

Type 2- Loops

• Circular or spiral pattern

• Has two deltas

• Four types:

• Plain whorl

• Central pocket whorl

• Double loop whorl

• Accidental whorl

• About 35% of people have whorls

Type 3- Whorl

Poll

Look at your left pointer finer... does it have an arch, loop or whorl print?

• Arch

• Loop

• Whorl

• Small details in fingerprints

• Help identify specific prints

• Common features:

• Ridge ending

• Fork (bifurcation)

• Island (dot)

• Crossover

• Core

​Ridge Features

Word Cloud

What makes finger prints special?

• Never change (except for scars)

• Unique to each person

• Can't be removed permanently

• Easy to collect

• Hard to fake

• Roll from side to side

• Use light pressure

• Cover the whole fingertip
  Avoid smudging

• Keep fingers clean and dry

​​When taking your own fingerprints....

Check the science resource sheet for a link to do your own fingerprints> https://drive.google.com/drive/folders/1rsI4PDxoRZm8PJoz2fueEJzmZxHgQI3a

Mrs. Coles will demonstrate how to take your own prints.

Materials Needed:

Pencil (regular graphite pencil)

Paper (any color)

Clear tape

White paper (for contrast)

Steps:

Rub the pencil: Scribble a thick patch of pencil on a piece of paper.

Press your finger: Rub your fingertip on the pencil patch to transfer the graphite.

Lift with tape: Press a piece of clear tape onto the fingerprint-covered finger and peel it off.

Stick to paper: Place the tape onto white paper, and you should see the fingerprint details!

Powder and Tape Method

This method mimics real fingerprint lifting techniques used in forensic science.

Materials Needed:

• Clear tape (packing tape or Scotch tape)

• Fine powder (cocoa powder, cornstarch, or fingerprint powder if available)

• Soft brush (makeup brush, paintbrush, or a clean, dry sponge)

• Dark or light surface (a glass, a countertop, or a piece of paper in a contrasting color)

Steps:

1. To make a fingerprint, Have the student press their finger on a smooth surface (like glass or a countertop). Oily or slightly sweaty fingers work best.

2. Apply powder: Lightly dust the area with cocoa powder (for light surfaces) or cornstarch (for dark surfaces) using the soft brush. Tap off excess powder.

3. Reveal the print: The powder will stick to the fingerprint’s ridges, making it visible.

4. Lift the print: Carefully press a piece of clear tape over the print, then peel it off.

5. Transfer the print: Stick the tape onto a piece of white or black paper to preserve the fingerprint.

Word Cloud

Where do we use fingerprinting verification in our every day life?

Interesting Facts

• Identical twins have different fingerprints

• Fingerprints form before birth

• They help us grip things better

• Some people are born without them

• They're mostly water and oil
  
  Alright... let's see who paid attention...

Multiple Select

What are the 3 main types of fingerprints?

• Divot

• Loop

• Arches

• Wholr

Open Ended

Why are fingerprints important?