Latent Fingerprints Essay

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.

Method used: I used my latent fingerprint dusting powder in order to bring the print to a visible state to the naked eye and then I used my tape I had to gain a copy of the print off the handle. I then took the evidence to my forensic vehicle in order to keep it secure for further examination.

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)

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

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

They first had to identify whether the body was indeed Tiernan’s or not and two days after the body was found, fingerprinting methods indeed determined that the body was Leanne Tiernan. Despite her body being found 9 months later, her body was still intact enough to gather fingerprints. Fingerprinting proves to be a critical method in forensic cases as no two individuals have been recorded having the same fingerprint, making it an ideal way to identify suspects or victims. Fingerprints are also individual characteristics making it nearly 100% chance that it could be traced back to a source. Getting something Tiernan may have touched can then be compared to a fingerprint(s) taken from her body. Fingerprints have ridge characteristics known as minutiae and can also be classified on their general pattern known as loops, arches, and whorls. Fingerprints also do not change unless damage is done to the dermal papillae, which makes fingerprints a powerful use of evidence. Extracting a fingerprint from Tiernan would require pressing a finger into an ink pad and then transferring the impression onto a card that would be examined by a professional. However, getting a sample to compare her fingerprint would require investigators to find a latent fingerprint (prints that are left on a surface which are invisible to the naked eye) of Tiernan. When we touch something, we leave impressions on surfaces due to the sweat and oil and as long as the

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

Fingerprints can be taken from a crime scene in various methods. Fingerprints are classified into three categories depending on the surface they are found. Fingerprints on soft surfaces are most likely to be three-dimensional plastic prints such as soap, wax, wet paint, fresh caulk, etc. (“A Simplified Guide To Fingerprint Analysis”, n.d). The fingerprints on hard surfaces are patent or latent prints including blood, dirt, ink, paint, etc. transferred from a finger or thumb to a surface (“A Simplified Guide To Fingerprint Analysis”, n.d). Patent prints can be collected using photography. The prints are photographed in high resolution with a forensic measurement scale for the image for reference. There are multiple methods for discovering and collecting latent prints. Alternate Light Source (ALS) use

Latent fingerprints found at crime sights or else developed in the laboratory are categorized by examiners as patent, latent, or plastic impressions1. The word latent means hidden or unseen. Latent prints are undetectable until brought out with a physical, chemical and fuming process. The physical developer is a means to detect fingerprints on dry and wet, including paper articles, clay-based products and adhesive tapes. Ninhydrin is one of the most widely used chemical reagents for enhancement of latent finger print impressions on porous substrates. Nonporous surfaces do not absorb. These surfaces repel moisture and often appear polished. They include glass, metal, plastics, lacquered or painted wood, and rubber. Superglue (cyanoacrylate) fuming is the best example for such non-porous substrate analysis.

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.

“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)

The introduction of the modern use of fingerprinting all started in 1984, when a British geneticist named Alec Jeffreys came across new methods for DNA fingerprinting (Jones, 2012). Since his discovery, this technique has been used successfully to identify perpetrators of crimes. For more than a century in fact, fingerprints have been used as identification tools by law enforcement. Known as “friction ridge analysis,” (Jones, 2012), this forensic method comprises of examiners comparing details of an unknown print against known prints. These details are analyzed

The use of fingerprinting as a means of identification was born out of the need of law enforcement officials to have permanent records that could determine if a convict had been previously arrested or imprisoned. Before the advent of fingerprinting, law enforcement used a number of different methods to try to accomplish this. Ancient civilizations would tattoo or physically maim prisoners. In more recent times, daguerreotyping (that is, photographing) was used, but proved to be less than reliable, because people had the ability to dramatically alter their appearance (Skopitz). As a result, this method too, became obsolete with the discovery of fingerprinting, an absolutely infallible

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.

Fingerprinting is used for many things, such as a robbery, or at a crime scene. Fingerprints were first discovered in 1870 by Alphonse Bertillon, who was a French anthropologist. In 1892, Juan Vucetich had made the first criminal report using a fingerprint. In 1905 America used fingerprints for identification. When America started using fingerprints for identification they had to match the fingerprints manually when needed. When technology was able to enter fingerprints, and match them with anonymous ones, it helped identification immensely.