Forensics CJ201 Fingerprinting

Sir Francis Galton

A British anthropoligist that pioneered fingerprints being used as means of Identification. He developed the classifications of the Loop, Whorl, & Arch

What was the first case that used fingerprinting evidence?

In 1892, in Buenos Aires Argentina, a murder was solved using thumbprint evidence found at the crime scene

What is a fingerprint?

Friction ridges found on the fingers, palms, and soles of the feet.

What makes you fingerprint unique?

Friction ridges are formed in the womb, they’re dependent on how the fetus interacts with teh womb and stay the same forever

What makes up a fingerprint?

oils, sweat, water, and amino acids. The liquids secret from the pores in the shape of friction ridges and is the transferred to a surface, creating a fingerprint

What are friction ridges?

Raised area of skin

What are furrow/valleys?

Indented area of skin

What are the physiological affects of latent prints?

Work history, hobbies, diet, heredity, dry or sweaty hands, missing or injured fingers

What are the environmental affects of latent prints?

Rain, wind, UV rays, dust, physical contact, surface texture, clothing or gloves worn by subject

What are the three types of prints?

Latent, patent, and plastic

What is a latent print?

A fingerprint that is invisible to the naked eye, requiring additional processing in order to be seen

What is a patent print?

A fingerprint made by blood, grease, ink, or dirt and is easily visble to the naked eye

what is a plastic print?

A three dimensional impression that is made by pressing your finger into fresh paint, wax, soap, or tar and therefore prints are easily visible to the naked eye

What are identification characteristics(Points of minutiae)

Ridge Endings: The point where the ridge ends suddenly, Birfuraction: A point where a single ridge branches out into two or more ridges, Ridge Dots: Very small ridges, Ridge Islands: Slightly longer than dots and are in the middle of two diverging ridges, Spurs: Notch protruding from a ridge, Bridges: Small ridges that join two adjacent ridges, Crossovers: Formed when two ridges cross each other

What are loops?

Prints that curve back on themselves to form a loop shape and have one delta

What are whorls?

Prints that form circular or spiral patterns like tiny whirlpools, creating at minimum two delta’s and sometimes three

What are arches?

Prints that create a wave like pattern and have plain arches and tented arches, has no deltas