Forensics Study Time!

what's the digitial imaging and how is it used in fp analysis? what's the greatest limitation in digital imaging?

a pic is converted into a series of square electronic dots known as pixels. used to compare fps and to enhance poor fp images. main limitation of it is that its only as useful as the images it has to work w/. if poor, cannot work

Who published the first book on the science of fingerprinting? What were the book's most important contributions to understanding fingerprints?

Francis Galton. No two prints are idenitcal, an individual's prints remain unchanged from year to year

The letter I and A in the acronym IAFIS stand for:

Integrated Automated. The Integrated Automated Fingerprint Identification System (IAFIS), is a computerized system maintained by the Federal Bureau of Investigation (FBI) since 1999. It is a national automated fingerprint identification and criminal history system.

Which animal has fingerprint patterns most similar to humans?

koala

What type of print is transferred onto a smooth surface by blood or other liquids making it visible?

patent

What type of fingerprint is shown in the diagram below?

plain whorl

A print that comes in and out on the same side is called

A loop

The Case of Will West caused what system to no longer be used?

Bertillon System Bertillon system The Bertillon System, invented by French criminologist Alphonse Bertillon in 1879, was a technique for describing individuals on the basis of a catalogue of physical measurements

To permanently alter fingerprints one must damage what?

Dermal papillae

What type of fingerprint is shown?

Double loop whorl

Who first introduced fingerprinting to the police as a system of identification?

Galton

Chemical methods for developing latent fingerprints must be used in the following sequence:

Iodine, ninhydrin, physical developer

Which person listed below attempted to destroy his fingerprints with corrosive acid?

John Dillinger

What type of print is an indentation left in soft materials such as clay or wax?

Plastic

Right hand

Radial loop

What's the dermal papillae? Why is it important in FPIng?

boundary of cells separating the outer portion of skin (epidermis) and inner skin (dermis). shape of it determines form and pattern of ridges on surface of skin. doesn't change throughout life, so ridge patterns dont change

What major advance in fingerprint tech was pioneered by Juan Vucetich and Sir Richard Henry? What was the importance of this advance?

creation of classification systems capable of filing many thousands of prints in a logical and searchable sequence. allowed law enforcement officials to quickly compare prints found at crime scene to known criminals to help identify possible suspects

What method would you use to lift a print off metal?

dusting

what phenomenon underlies many of the new chem techniques used to visualize latent fps? why is this phenomenon so valuable in fp visualization?

fluorescence! substances that emit light or fluoresce are more readily seen w/ either the naked eye or through photography as compared to non-light-emitting materials. thus, techniques based on fluroescence permit better visualization of all prints and allow the visualization of faint prints that other methods may fail to visualize

What aspect of a fingerprint determines its individuality?

identity, number, relative location of ridge characteristics impart individuality to a FP

a latent fingerprint

is not visible to the naked eye

Describe each of the three classes of FPs. whichh class is most common, which is least

loops, whorls, arches. loops- ridge lines that enter from one side of pattern and curve around to exit from same side of pattern whorls- ridge patterns that are generally rounded or circular in shape and have two deltas arches - ridge lines enter from one side and flow out the other loops most, arches least

Why is it almost impossible to obscure one's fingerprints by surgery or mutilation?

must reach deeply enough into skin to damage dermal papillae. would be totally impossible to obliterate all ridge characteristcs on hand. attempts would create deep scars that'd provide new characeristics for identifying prints

What is the most commonly used chemical method to visualize latent fps on porous materials? if this method is unsuccessful, what other technique typically is used?

ninhydrin method is most commonly used, if it fails, the physical dev technique is typically used

Brielfy describe how the automated fingerprint identification system (AFIS) creates a FP image. What characteristics of the FP does the AFIS record for comparison

scans FPs and converts them into digital images that contain data on the relative location and orientation of ridge characteristics. The system records the points where ridges terminate, the points where they branch into two ridges, and the relative position and orientation of each ridge characteristic

What aspect of FPS form the basis for primary classification under FBI system, what is the main drawback of FBI system

the presence or absence of whorl pattern is the basis for determining the primary classification in FBI system. main drawback is that it's only useful when a full set of FPs are available

list two types of specialized fp powders and name one advantage each has over traditional fp powder

two specialized fp powders are magnetic sensitive powder and fluorescent powder. - using magnetic sensitive powder offers less chance that the print will be destroyed or damaged b/c the powder is spread using a magnetic brush that has no bristles to come in contact w/ the surface containing the print. - fl. powders reveal a vivid image of a print under uv light. when the developing print is photographed under UV light, the color of the surface will not obscure the print.

This fingerprint was taken from the LEFT hand. What is the SUBGROUP of this fingerprint?

ulnar

Left hand

ulnar loop

List and describe the three types of FPs that may be found at the crime scene

visible prints are made when a finger deposits a visible material such as ink, dirt, or blood onto a surface. plastics are ridge impressions left on a soft material such as putty, wax, soap, or dust. latent or invisible prints are impressions caused by the transfer of body perspiration or oils present on finger ridges to the surface of an object

what's the final step in FP identification? Why's this step necessary if a computerized database of fingerprints is available to the forensic scientist?

visual comparison of the prints in question by trained examiner. a computer database can only produce a list of prints that are similar to the print in question; it can't make a pos idenitifcation

When should a fp be lifted from a crime scene? describe how to life and preserve a fp using adhesive tape

when on a large, immovable object. one method is to dust the print w/ fp powder, then cover the print w/ adhesive tape. when tape is pulled up, the powder is transferred to the tape. then the tape is placed on a card that provides a good bg contrast w/ the powder

What type of fingerprint is this?

whorl