Fingerprints chapter 14

What are fingerprints

Reproduction of friction and skim ridges found on the palm side of the fingers and thumbs

What is the first fundamental principle of fingerprints

Fingerprints is an individual characteristic; no two fingers have yet been found to possess identical ridge characteristics

What imparts individuality to a fingerprint

Identity number and relative location of ridge characteristics

What are ridge characteristics? What is another name for ridge characteristics

Ridge endings, birfurcations,enclosures, and other ridge detials which must match in teo fingerprints to establish common origin.they are also known as minutiae

What is the second fundamental principle of fingerprints

Fingerprints remains unchanged during a individuals lifetime

What are dermal papillae and how are they related to fingerprints

Cells form a boundary between the outer skin or epidermis and the inner skin or the dermis. The shape or boundary determines the form and pattern of ridges on the surface of the skin and thus the fingerprint pattern

What is a latent fingerprint? Describe how they are formed

A fingerprint made by deposit of oils or perspiration that is indivisible to the naked eye. They are formed when touching a surface and transfers perspiration along with oils that may have been picked up by touching hairy portions of the body onto the surface thereby leaving an impression of the fingers ridge pattern

Why is it pointless to try to obscure or obliterate ones fingerprint by scaring or otherwise damaging the tissue

The wound would have to penetrate 1 to 2 milli meters beneath the skins surface. Scars provide new characteristics for identification

What is the third fundamental principle of fingerprints

Fingerprints have general rude he patterns that permit them to be systematically classified

What are the three types of fingerprints? Which is the most common

Loops whorls and arches. Loops are the most common

Which class of fingerprints includes ridge patterns that are general rounded or circular and have two deltas

Whorls

Which type of fingerprint pattern must have at least one delta

A loop

Which is the simplest of all fingerprint patterns formed by ridges entering from one side of the print and exiting on the opposite side

A plain arch

What is the primary classification? What is the basic for this classification

Classifying fingerprints under the FBI system. The presence or absence of the whorl pattern is the basis for determination for primary classification

What is an AFIS and what is the heart of AFIS technology

automated fingerprint identification system. Ability of a computer to scan and digitally encode fingerprints so that they can be subject to high speed computer processing

When using AFIS who makes final verification of a prints identity

Fingerprint experts

What is livescan? What procedure has livescan largely replaced

Ink less device that. Captures digital images of fingerprints and Palm prints and electronically transmits then to an AFIS. It ha s largely replaced the procedure of manually inking fingerprints and rolling inked fingers into a standard ten print card

Name two drawbacks to using AFIS

A latent print didn't make a hit on the AFIS system due to poor quality of print

State AFIS often do not communicate with each other directly and states can frequently share fingerprint information

Name three kinds of crime scene fingerprints

Visible prints latent prints and plastic prints

How are prints from hard and non absorbent surfaces preferably developed? How are soft and porous surfaces generally treated

Prints hard and nonabsorbent surfaces are preferably developed by applying fingerprint powder or treating with super glue. Soft and porous surfaces are treated with one or more chemicals

What is RUVIS and how does it work

Reflected ultraviolet imaging system.locates prints on the most nonabsorbent surfaces without the aid of chemical or powder treatments. This system aims uv light at the surface and strikes the fingerprint differentiating the print from its background surface.

Name four common chemical methods for visualizing latent prints

Fuming ninhydrin physical developer and superglue fuming

Explain how latent prints can be visualized when illuminated by laser light

Perspiration in fingerprints contains a variety of components that fluoresce when illuminated by laser light

Name three reasons why alternate light sources have replaced lasers for visualizing latent prints

Light can be passed by several filters giving more flexibility in selecting wavelength of light to be aimed at the latent print

Alternate light sources are commercially available at costs significantly below those of laser illuminators

Alternate light sources are portable and can be readily taken to any crime scene

What is the first thing that the criminalist must do after visualizing a print but before making any further attempted to preserving it

Take a photograph

Describe how the criminalist should handle prints on small objects

If small enough to be transported without destroying the print it should be persevered in its entirety. The print should be covered in cellophane so it will be protected from damage

Describe basic process use to lift a fingerprint. When should this procedure be used

A powder is applied to a print and the surface containing the print is covered with the adhesive side of the tape. When the tape is pulled up the powder is transferred to the tape. The tape is placed on a properly labeled card. This procedure is used on large or immovable objects

What is digital imaging? How is it useful for analyzing fingerprints

Process through which a picture is conveyed into a series of square electronic dots known as pixels. By using digital imaging fingerprints can be enhanced for the most accurate and comprehensive analysis

Under what conditions is digital imaging not effective in enhancing latent fingerprints

Digital imaging is not effective in enhancing latent fingerprints if details of the print do not exist on the original images

A verbal description of a perpetrators physical characteristics and dress provided by eyewitness

Portrait parle

A system of identification of individuals by measurement of parts of the body developed by Alphonsus Bertillion

Anthropometry

A class of fingerprints characterized by ridge lines that enter one side of the pattern and curve around to exit from the same side of the pattern

Loop

A class of fingerprints that include Ridge pattern Saturday generally rounded or circular and have two delta

Whorl

A class of fingerprints characterized by Ridge lines that have entered the print from one side and flow out the other side

Arch

The fingerprint made when the finger deposits of visible material such as Inc. dirt or blood on to the surface

Visible print

A fingerprint impressed In a soft surface

Plastic Print

A technique for visualizing latent fingerprints by exposing them to iodine vapors

Iodine fuming

A physical change from the solid directly into the gaseous state

Sublimation

A chemical reagent used to develop latent fingerprints on the porous materials by reacting with amino acids and perspiration

Ninhydrin

A silver nitrate based reagent formulated to develop a latent fingerprints on porous surfaces

Physicla developer

The technique for visualizing latent fingerprints on non-poor services by exposing them to vapors name for commercial product superglue

Super glue fuming

To emit visible light when exposed to light of a shorter wavelength

Fluoresce