Fingerprint Development Essay

Introduction The purpose of this lab was to introduce chemical development as a way to develop latent fingerprints and to demonstrate two of these methods: cyanoacrylate fuming and iodine fuming. These two methods are regularly used to develop latent fingerprints. Cyanoacrylate (or superglue) fuming was discovered as a way to develop prints in the late 1970s. The fumes of heated cyanoacrylate react with the bodily fluids of a fingerprint.

Any moist or wet biological evidence (blood, body fluids, plants, etc.) like the lottery ticket on the counter with the blood smeared print on it should be collected wearing gloves it should then be placed in a clean unused paper container such an envelope, and or small bag and transported back to an evidence receiving area, it should then be taken out of the bag and allowed to air dry thoroughly. The Ninhydrin process should be applied to this piece of evidence to obtain noticeable prints.

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.

During the identification phase, the user puts the finger on the same sensor, generating a new fingerprint image or template called query print. Minutiae points are carried out from the query print, and the matcher module compares the set of query minutia with the stored minutia templates or image in the enrollment database to find the number of similar minutia points. Because of variations present in finger placement and pressure applied to the sensor, the minutia points take out from the template and query fingerprints must be lined up, or submitted before matching. After line up the fingerprints, the matcher decides the number of pairs of matching minutiae-two minutiae points that have similar location and directions. The system decides the user's identity by comparing the match score to a

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)

After Galton’s discovery, the use of fingerprinting by law enforcement was inevitable. In 1892, an Argentine police official, Juan Vucetich, became the first person to identify a criminal through fingerprints (The History of Fingerprints). The last major step necessary for the widespread use of fingerprint identification was to create a classification system that simplified the process of matching fingerprints. That came in 1901, when Edward Henry devised a system that separated fingerprints into four different categories - loops, whorls, arches, and composites (Skopitz). Shortly after its development, most European nations implemented this system of

Fingerprint comparison has always interested me because of the uniqueness in friction ridge detail. As a fingerprint expert, you learn that there are no two individual in the world that have the same fingerprints. Individuals can share the same DNA but their fingerprints will always be different. Examiners may be able to find two fingerprints that have many of the same characteristics, but not exactly the same as in the case of the Madrid bombing. The basics of fingerprint comparison will always be the same. However, it fascinates me how procedures change, and make fingerprint comparison more of a science.

The final main biometric technology used is fingerprint recognition. This is definitely the most widely used biometric technology. This type of biometric has been used for many, many years. Because of this, fingerprint recognition has been known as the most primary and accurate identification method used to identify a person. The modern fingerprint recognition is all done electronically. There are two main ways of analyzing fingerprints electronically. The first plots points on the ridges of a person’s fingers that enable the computer to compare to different fingerprints. The second method uses patterns of a fingerprint

“Fingerprint recognition is one of the divorce inference using the impressions made by the minute ridge formations or patterns found on the fingertips. No two people have exactly the same arrangement of the ridge patterns, and the remaining patterns of any one individual unchanged. Fingerprints infallible provide a means of personal identification. Other personal characteristics may change, but not fingerprints”. (1)

In a case where a bloody fingerprint is not exactly defined very well blood enhancement reagents may be considered. These reagents are typically applied with a very fine spray in order to keep from washing the print away. Many enhancement reagents are based on peroxidase reaction. Other reagents such as Coomassie Blue actually dye the print making it more enhanced. Certain recipes produce a reagent that must be made shortly before using due to he short

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 first step in processing fingerprint evidence at a crime scene begins with documentation through the use of photography, sketches and detailed notes on the condition and disposition of the evidence. Often, latent prints can be used to establish the identity of a suspect or victim at a crime scene and can be considered as one of the most valuable forms of physical evidence. Processing evidence at a crime scene is a long, tedious process to ensure that delicate evidence, such as fingerprints can be preserved. When processing fingerprints, the location and condition of the print should be identified to determine the most appropriate technique for processing. There are two primary types of surfaces: porous and non-porous. Porous surfaces absorb fingerprint residue like paper, cardboard or unfinished wood. Conventional chemical techniques used on these types of surfaces include Silver Nitrate, Iodine Fuming, Ninhydrin and SuperGlue Fuming. Non-porous surfaces consist of plastics, glass, and metal. These prints are usually lifted with the powder dusting technique; however, caution should be used while processing latent print residue on non-porous surfaces as they can easily smear. Powdered latent prints are then lifted with tape. (Lee, & Gaesslen, 2001)

It is no secret that criminals are always in search of means to effectively destroy any evidence that may implicate them in a crime, particular involving friction ridge skin as it is often speculated to be the most damning form of of evidence that exists. This is due to the undeniable uniqueness of fingerprints that remain unchanged throughout a person’s lifetime (Holder, Robinson & Laub, 2011). Over time efforts to destroy friction ridge skin evidence have included methods of water to wash away the latent print evidence, not a shocking concept once we think about how vast bodies of water occupy over 70% of the earth’s surface (Williams, 2014). Therefore, as a means to examine the effects of water submersion on latent fingerprints, an experiment was conducted to identify the impact four variants of water solutions have on latent fingerprints.

Fingerprints are an important part of criminal investigations. They are used to help identify a person because each person has a unique type of print. We use fingerprints because, unlike any of the other identifying marks on the body, they very rarely change. Over the years the way we identify people has changed over the years.

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.