Forensic Bio Unit 5

Footprint impressions from casts and/or by photography will give investigators information about what?

The number of people present at the scene (perpetrators). Points of entry and exit. Positions of perpetrators(s), victim(s) and witness(es). Direction(s) of movement/travel and pathway(s) through the crime scene. Time period, from short-lived impressions in frost, snow, dew.

What does it take to determine a fingerprint match?

The old system required 16 points to match Other countries use 8, 10 and 12 points or no numerical standard Recently, a non-numerical standard has been implemented. The fingerprint match is a matter of opinion by the expert & therefore cannot be quantified

What was the progression of fingerprint history?

1686: Marcello Malpighi, first to notice *patterns of skin on fingers is distinct* 1823: *Whorls, ellipses, and triangles* identified by Jan Evangelista Purkinjie 1858: Sir William Herschel, *used fingerprints on contracts in India* - may have known of the individual identification associated with fingerprints 1880: Fingerprints used by Henry Fauld to *identify criminals* 1892: Galton developed the *classification of fingerprints*

Fingerprinting history continued

1896: System of matching fingerprints to identify people developed by Edward Henry 1900: Scotland Yard adopts the Henry system of fingerprinting 1902: First person was convicted on fingerprint evidence 2013: The Integrated Automated Fingerprint Identification System (IAFIS), is the USA national fingerprint and criminal history system

How is footwear evidence recovered?

All shoeprints should be recovered from the scene. (brand of shoe, etc is important bc we can look at how rare the shoes are) Scene should be controlled to prevent destruction of evidence. Some prints can be visualised by darkening a room and using a bright light at a low angle. Shoeprints should be documented: Location recorded and photographed. Objects with shoeprints should be removed if possible (glass) If can't be removed, an *examination quality* photograph should be taken. Ruler: allows for enlargement to real size

can be used to eliminate a suspected shoe or suggest a shoe could have made the impression. examples are size & pattern

Class Characteristics (such as size or pattern)

How do you know whether a loop is a radial or ulnar loop?

Depending on which direction the opening of the loop is pointed towards. If opening toward the thumb, it is radial. If opening toward the little finger, it is ulnar

_ is the process by which a picture is converted into a digital computer file. An important and useful tool, especially for fingerprint identification, is the_that places two images side by side and allows the examiner to chart the common features on both images simultaneously.

Digital imaging - With the help of digital imaging software, fingerprints, which are often not in perfect condition, can now be enhanced for the most accurate and comprehensive analysis. (useful but can't be submitted to court) Photographs of fingerprints are often taken before they are dusted for. compare function

After photo, 2-D print can be lifted via which methods?

Electrostatic Lifting:A charge is used to lift dry materials from surface to black film.The background can provide more contrast.Photographed for evidence Dusting:Fingerprint powder can visualise print

How do you identify what kind of whorl is in a fingerprint?

First identify the 2 deltas Draw a line between the 2 deltas Draw a line around the outermost ridge which forms a complete circle See whether or not the imaginary line intersects the line drawn around the ridge. If the line intersects, it is a plain whorl. If the line does not intersect, it is a central pocket whorl.

credited for first fingerprint from a crime scene (a greasy fingerprint left on an alcohol bottle)

Francis Galton

proved that fingerprints are unique to the individual & that they are permanent, lasting for an entire lifetime

Henry Fauld

can be used to identify an exact shoe. However, these can change over time

Individual Characteristics

the capture of fingerprint and palm images using an electro-optical computerised device.

Livescan - used to capture fingerprints & palm prints, which can be a unique identifier as well. Palmprints were not previously recorded using the old ink method

What is the most common, next most common, and least common fingerprint pattern?

Loops - most common (about 60% of all fingerprints) Whorls (~35%) Arches - least common (~5%)

How are shoe prints evidence?

Most perpetrators wear shoes. Footprints are almost always left, it is whether they can be located and differentiated from other prints which is important for forensic science. It can be difficult to ascertain which prints are relevant to the crime.

Do identical twins share fingerprints?

NO - even identical twins have unique fingerprints. In a case where identical twins are involved, investigators should look for fingerprints which will identify one of the twins

What are fingerprints used for?

Not only for criminals, but also to track people (such as in airports, particularly immigration).

The study of the uniqueness of friction ridge structures and their use for personal identification.

Ridgeology: The term "ridgeology" was coined by Sergeant David Ashbaugh to describe the scientific evaluation process used for friction ridge identifications.

What else can footprints tell us?

Sequence and manner (walking, running, limping, staggering) in which the impressions were created. Links between crime scenes, e.g. the same individualss committing several crimes in one evening. The type, size and areas of specific wear on the shoes. Certain seasons or weather conditions lend themselves to the creation of footprint impressions than others. Soil trapped in soles can also give useful leads, such as soil pH, specific minerals or heavy metals in the soil, the presence of seeds or pollen grains.

first person to use fingerprints to link documents to people

Sir William Herschel (used fingerprints on contracts in India)

the USA national fingerprint and criminal history system

The Integrated Automated Fingerprint Identification System (IAFIS), run by the FBI Extremely effective system - we can an enormous # of fingerprints on the database, generates a match (or determines that there is no match) in 27 minutes. the system is available 24/7/365 - this speed and availability has a great impact on the speed of the investigation process

How can the brand of a shoe be used forensically?

The brand of the shoe can be tied to the shoe pattern to determine the type of shoe. If the particular shoe is very rare, this can help us narrow our suspect pool.

Shoeprint made in soft material (dirt, snow) Requires making a cast of the print Composition of dirt or snow will determine the detail of the impression

Three dimensional impression As with the 2D print ,you start by photographing the print. Then you try to preserve the print for analysis by making a cast of the print (with plaster of paris or dental stone). You must first seal the print (such as with hairspray) so that the liquid poured in doesn't move or damage the print. Once the cast has been set, it can be removed & then left for another 24 hrs to dry completely prior to brushing off any soil or debris attached to the cast.

Three different types of footwear impressions/shoe prints:

Two dimensional (visible) Two dimensional print (latent) Three dimensional impression

Dirt or other material picked up by shoe and deposited onto flat, hard surface. Variety of surfaces and materials deposited makes recovery of these prints complex.

Two dimensional footprint (visible)

Can leave behind barely visible impressions in dust Can leave impression in polish or wax

Two dimensional print (latent) Different reagents can be used to make the latent prints visible. For example, if the footprint is in blood, luminol can be used to enhance the print. This can be done at the scene or if the print can be removed (such as on a tile) it can be done back at the lab. It can be useful to perform the enhancement at the scene, because it can then be made clear how someone moved about the crime scene.

Can fingerprints persist after death?

YES, which can prove useful for post mortem identification NO 2 FINGERPRINTS ARE IDENTICAL. No 2 fingerprints have been found to be the same to date, even when comparing relatives or identical twins.

applied to fingerprints which consist of a combination of 2 or more patterns, or a pattern that doesn't fit into any of the classified categories

accidental whorl (rarely do you see more than 1 of these present)

Latent prints may be collected by revealing them with a dusting of_ or _ powder and then lifted with a piece of _.

aluminum or black powder / clear tape Camel hair was the most common animal hair used to make fingerprint brushes. But now many brushes are made out of fiberglass or other animal hair such a squirrels'.

Accounts for 5% of all fingerprint types the simplest type of fingerprints that are formed by ridges that enter on one side of the print and exit on the other. No deltas are present.

arches: plain & tented

minutiae point where one ridge splits into 2 and forms a fork

bifurcation (very common on fingerprints. comparisons can be made between crime scene & suspect using bifuractions)

In latent fingerprints, the ridge structure is reproduced on an object in sweat, oily secretions, present on the fingers. Most latent prints are colorless and must therefore be "developed," or made visible, before they can be preserved and compared. How is this done?

brushing them with various gray or black powders containing chalk The latent impressions are photographed or lifted using adhesive surfaces of tape. The method of development depends of the surface type and color.

How is an examination quality photograph of a footprint taken?

by placing a ruler next to the footprint when taking the picture. this allows for enlargement to real size. The size of the shoe can give us a rough idea of the height of the person.

Fingerprints used to be collected on _, but the current method is to_fingerprints which can be uploaded to a database for analysis.

cards scan

3-D impression can be highlighted by Spraying with _

colored wax spray

minutiae point where one ridge crosses over another, making a characteristic X shape

crossover

form a small triangle

delta

the area of the pattern where there is a triangulation or a dividing of the ridges.

delta (small triangle) A "loop" must have a single delta & a ridge that enters & leaves on the same side

Loops must have one _ and one or more_ that enter and leave on the same side. These patterns are named for their positions related to the _and _bones.

delta/ ridges can either be a radial loop (opening of loops is toward the thumb) or an ulna loop, depending on the direction of the ridges (opening of loop is toward the little finger)

made up of 2 loop patterns in combination, often taking on an S shape

double-looped whorl

Fingerprints can be deposited how?

due to natural secretions of the ecrine gland, present within the friction ridge of the skin the secretions are primarily water. each ridge is dotted with pores, any of which secretions can come. a secretion occurs when we touch anything by pressing our fingers into ink, the ink transferred onto the peaks of the ridges can make an impression if pressed onto paper

a procedure that doesn't involve powders, that is used to develop latent fingerprints on a variety of objects.

ethyl cyanoacrylate fuming method (often called the superglue method) - can only be used on non-porous surfaces cyanoacrylate polymerizes the fingerprint to the surface it's on by polymerizing the oils from the fingerprint. it creates a print that can be lifted several times. after placing the object in a chamber with the ethyl cyanoacrylate fumes, black powder is applied to the object so that the print(s) can be lifted with tape. The tape is then adhered to a fingerprint card which can be analyzed.

an impression of the friction ridges found on fingers - why did they evolve?

fingerprints evolved in primates to help with gripping surfaces, provides greater concentration of nerve endings & enhances sensory feeling of touch. Furrows separate the ridges. Complex patterns are formed which remained unchanged throughout one's lifetime. Our fingerprints are very similar to chimps'

to help find latent prints on multi-colored or dark surfaces.

fluorescent and phophorescent powder and UV lights

How are fingerprints classified?

in a three-way process: by the shapes and contours of individual patterns, by noting the finger positions of the pattern types, by relative size, determined by counting the ridges in loops and by tracing the ridges in whorls.

very short fragments

island - look like islands in a sea of other ridges

one of the few mammals other than primates which has fingerprints

koalas - very similar to humans' & chimps' fingerprints

Invisible to naked eye, left behind when oils and perspiration are transferred from a finger to an object. Must be enhanced to make them visible.

latent prints

_can also be used to reveal latent prints. This type of powder works better on shiny surfaces or plastic containers.

magnetic powder

Arch in which Ridges enter on one side and exit on the other side.

plain arch

Touch soft substance such as putty, soap, paint, etc. actual impression of ridges.

plastic prints

minutiae point which lines the ridge, where oil & sweat are secreted

pores/cores (may not be present in all fingerprints)

minutiae point where ridge endings exist

ridge ending

A fingerprint is made of a series of _ and _on the surface of the finger. The uniqueness of a fingerprint can be determined by the_of ridges and valleys as well as the location, shape, and position of _, which are points where the ridge structure changes.

ridges & valleys pattern minutiae points:points where the ridge structure changes

Arch in which has a spike in the center.

tented arch

Friction ridge pattern forms in_.The friction ridge arrangement is determined by _.

the fetus about 28 wks after conception dermal papillae - layer of cells which separates epidermis from dermis If you damage the outer layer of skin without damaging the dermal papillae, it will not alter the friction ridge pattern (fingerprint). If you have a deeper cut/wound which damages the epidermis, dermal papillae & dermis, the friction ridge pattern will be permanently altered due to scar tissue. (this will only affect the part of the print that was damaged)

Most countries use fingerprint analysis & store fingerprints on a database, classified by _

the main feature present on the center of the print

In contact with paint, blood, grease, ink, chalk dust etc. Visible ridges

visible prints

3 different types/forms of fingerprints

visible prints, plastic prints, & latent prints Locating visible or plastic prints at the crime scene normally presents little problem to the investigator, because these prints are usually distinct and visible to the eye.

on the sole, unique to each shoe & dependent on how a person walks - and how long they have worn the shoe

wear pattern

Human fingerprint patterns fall into three main groups:

whorls, loops, and arches.

Accounts for 35% of all fingerprint patterns, have at least one ridge that makes a complete circuit. They also have at least two deltas.

whorls: plain, central pocket, double-looped and accidental