Forensics- Chapter 6: Fingerprints

Fingerprint is made up of a series of

Ridges and valleys

Developed the classification system.

Sir Francis Galton and Sir Edmund Richard Henry

Silver Nitrate

Uses: wood, styrofoam Application: object dipped or sprayed Latent print color: black or reddish brown under uv light

Discouraged that everyone has a different arrangement of patterns on their fingers that do not change with time.

William Herschel

Is it possible to alter fingerprints?

Yes, fingerprints may be altered. John Dillinger tried to alter his but he essentially made his prints more unique.

Can fingerprints be taken from a dead body?

Yes, they chemically treat them to puff them out or surgically removing them.

Is fingerprint identification reliable?

Yes. Everyone's prints are different. No two people have the same fingerprints, they will not change as they age.

Prints visible to the naked eye

Patent prints

Plastic Prints (indentations)

Prints left by pressing into a soft surface

Patent fingerprints (visible/direct)

Prints left in a colored substance

Latent Prints (invisible/indirect)

Prints left in the sweat and oils from the skin

Arch

A fingerprint pattern that all ridges come in on one side and exit the other.

Loop

A fingerprint pattern that has at least on ridge entering one side and exiting the same side.

Points of similarity needed in the US?

12 points

Name two rare genetic conditions in which people are born without fingerprints.

1: Dermatophobia Pigmentosa Reticularis (DPR) 2: Ectodermal Dysplasia

Name three uses of fingerprints.

1: Link a suspect to a scene. 2: Identifying bodies. 3: Grip objects.

Describe three methods preciously used by CRIMINALS to try to alter their fingerprints.

1: Putting acid or chemicals on their fingertips. 2: Surgically removing them. 3: Switching their fingerprints upside down in surgery.

List the 3 fundamental principles for fingerprints.

1: a fingerprint is an individual characteristic, no two people have been found with the same fingerprint 2: patterns will stay the same throughout the persons life. 3: ridge patterns allow them to be identified systematically

Who was credited with solving the first murder using fingerprints?

Alphonse Bertillon

List 2 new technologies or gadgets in which fingerprints are needed.

An iPhone 5S and a safe

Simplest fingerprint pattern?

Arches

AFIS

Automated Fingerprint Identification System

What is the reason why even identical twins have different finger prints?

Blood flow

What is the name of the person falsely accused of being involved in the Madrid Bombing? What was the reason of the mistake?

Brandon Mayfield. The actual criminal and himself had similar fingerprints.

Describe the basal layer.

One of the three layers of the skin. Creation of fingerprints occurs here. New skin cells are produced here.

Dactylograms

Fingerprints

Describe how fingerprints are formed.

Fingerprints are formed at the 10th week of gestation in the mothers womb when the fetus is just inches long. When the basal layer creates new skin cells and they FOLD and BEND to create patterns.

IAFIS

Integrated Automated Fingerprint Identification System

Who is known as American public enemy #1 in the history of the US? What did he do to try to change his identity?

John Dillinger, he dipped his fingerprints in acid to burn off the first layer of the skin.

Invisible to the naked eye

Latent prints

Most common type of fingerprint pattern?

Loops

List the three patterns of fingerprints and sub-patterns with percentages.

Loops(65%): Radial and Ulnar Whorls(30%): Plain(24%) Central Pocket(2%) Accidental (0.01%) Double(4%) Arches(5%): Tented(1%) and Plain(4%)

What make sour fingertips moist and able to grip better?

Microscopic sweat pores

Ridge Impression/ Ridge Pattern

The pattern left behind by an individual's fingerprint.

Dactyloscopy

The study of fingerprint identification.

KOALAS have fingerprints that more closely resemble humans than CHIMPANZEES.

True

Ninhydrin

Uses: Paper Application: object dipped or sprayed (Wait 24 hours) Chemical Reaction: reacts with amino acids Latent print color: purple-blue print

Cyanoacrylate Vapor

Uses: household items Application: reacts with amino acids Latent print color: white print

Iodine Fuming

Uses: paper cardboard Application: in a vapor tent Latent print color: brownish print (fades quickly)