Phase 2: Visible Light Excitation

Latent fingerprint was excited with U.V light. This was done to see if the latent fingerprint shows fluorescence. Multiple photographs were taken with different settings, which included spectral filters, camera settings, and U.V light settings to find out if any fluorescence is displayed by the fingerprint residues and if so, to which extent it enhances the ridge characteristics of the fingerprint.

Lee, H. (2001). Advances in Fingerprint Technology, Second Edition, 2nd Edition. Retrieved January 26, 2015, from Vital Source: http://online.vitalsource.com/books/9781420041347

For over a century fingerprints have been one of the most used tools of forensic science. Fingerprints have been used to identify criminals of small crimes

Explain the principles and processes used in the analysis, comparison, evaluation, and verification of latent fingerprints. Latent prints are formed when the body’s natural oils and sweat on the skin are deposited onto another surface. Latent prints can be found on a variety of surface they are not readily visible and detection often requires the use of fingerprint powders, chemical reagents or alternate light sources. Generally speaking, the smoother and less porous a surface is, the greater the potential that any latent prints present can be found and developed. Investigators often perform cyanoacrylate processing, or fuming, of a surface before applying powders or dye stains. This process, typically performed on non-porous surfaces, involves exposing the object to cyanoacrylate vapors. The vapors will adhere to any prints present on the object allowing them to be viewed with oblique ambient light or a white light source. (Latent, n.d)

samples of an individual’s fingerprint’s can be lifted from a crime scene. The breakthrough of

The purpose of this experiment was to investigate a crime scene. Given an evidence bag a number of tests were performed in order to determine who the suspect was. The experiments included a simple fiber burn test, iodine fuming to develop a finger print, and thin-layer chromatography to determine ink similarities.

Though Hershel, Faulds, Galton and others set the stage in methods to indicate fingerprints should have been used for identification there was still controversy around the science. With the advances of technology, we now have a better understanding of why fingerprints have only been identified to a single individual. They are unique and permanent. Embryology finds six weeks in utero formations of early notching for what will become fingers starts. By week seven, webbing of the finger is almost gone and volar pads start to form. During week ten through twelve, initial formation of epidermal ridges begin. Primary ridges begin at the apex of the volar pads, tip of the finger and just above the first joint. Secondary ridges start to form by week sixteen and stop the formation of primary ridges. By twenty-four weeks ridge formation has completely finished. For over one hundred years friction ridge impressions have been only known to relate back to only one source thus resulting its broad usage in law enforcement, banking, government buildings for identification purposes and etc.

For the past several decades, ninhydrin has been used in the development of fingerprints from surfaces. The fingerprints revealed by ninhydrin have been used to compare against other known fingerprints, whether from the person of interest or a database, which can lead to a match on a victim or a suspect on a case. But what about the fingerprints that do not have a match in a database? Can that print be of any use to forensic scientists? In the journal article, “New Horizons for Ninhydrin: Colorimetric Determination of Gender from Fingerprints” the researchers attempt to determine if a fingerprint can yield more than just a picture that can be used for comparison.

Fingerprint residue is composed of endogenous amino acids, fatty acids, sterols, squalene and wax esters which change in concentration with time. Additionally, they create several intermediates and products which correspondingly change in concentration as they decompose and oxidize with time.

FINGERPRINT EXPERIMENT2AbstractLatent print residue is a combination of many substances excreted from the body. Latent print residues may be left from natural sweat on the skin or from a contaminant such as motor oil, blood, ink, paint or some other form of dirt. They may exhibit only a small portion of the surface of a finger and may be smudged, distorted, overlapped by other prints from the same, or from different individuals, or all of these in combination. The factors that affect the quality or presenceof latent prints include the conditions involved between friction skin contact and the objects that are touched. Pre-transfer conditions describe the condition of the friction skin and the amount and type of residue on the skin; and are affected

The amount of information that can be obtained through someone’s hands is astounding. One can determine the years of scarring from hard work, or the blisters from misuse. The most information can be obtained at the very tips of fingers, and what they leave behind. Fingerprints supply great evidence to help identify who was there, and possibly how many people were there. However, the problem becomes that there are too many prints found at one scene. It is difficult to try and determine when they were made based on physical appearance and common techniques. Nowadays, the age determination of latent prints can be achieved with a new approach using the sweaty residue of latent prints, and a small electrical charge.

They run the fingerprints in the system real fast, it is like it only takes two seconds for the to find a match to the prints. They also can use any type of print it doesn’t have to be a full print. In reality, you may not always get a visible print on everything. Sometimes you might have a non-porous print, and you have to put the material in a chamber an add drops of heated superglue. The fumes will harden on the fingerprint and then make them visible.

Even with the advanced state of forensic sciences some surfaces and circumstances prove difficult to successfully lift, or even detect, fingerprints from. There are now several methods of enhancing latent fingerprints for collection. These methods use chemicals, light sources and other techniques to enhance latent ridge marks on materials that prove difficult to successfully identify and lift prints from. These surfaces include certain types of metals, porous surfaces, and certain kinds of paper. We will discuss three types of latent finger print enhancement that are relatively new or still in the beginning stages of testing, two chemical, elctrochromism and yellow

The variety of foreign materials that might be found in a latent fingerprint deposit is virtually unlimited. The actual composition evidently depends on what the person has handled prior to the deposit of the impression. While it would be impossible to list them all, a few of the more likely materials include:

Every time somebody touches something, they leave behind a unique signature that forever links them to that object. This link is their fingerprints, which are unique to every person, for no two people have the same set, not even family members or identical twins. Palms and toes also leave prints behind, but these are far less commonly found during crime scene investigations. Therefore, fingerprints provide an identification process that is applicable to background checks, biometric security, mass disaster identification, and most importantly, crime scene investigations. Fingerprints are so differentiated because they are made up of distinct patterns of ridges and furrows on the fingers. The ridges are the “raised” portions of the prints, and the furrows are the “recessed” portions. This perceived uniqueness has led some people to falsely accept fingerprint analysis as absolute scientific fact. Although overall fingerprints are reliable, there are definitely situations where their accuracy can come into question.