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 FBI houses numerous units. The first unit being the Latent Print Unit (LPU). The LPU “examines and compares friction ridge detail of latent prints using the Automated Fingerprint
Minutia points represent positions where friction ridges end abruptly or where a ridge branches into two or many more ridges. A typical good-quality fingerprint template contains 20-70 minutiae points; the actual number depends on the size of the finger sensor surface and how the user places his or her finger on the sensor. The system stores the minutiae information position and direction along with the user's demographic information as a template in the enrollment database.
In quadrants 1 and 2 how the amount and constituents of the fingerprint residue on the substrate affects the fingerprint image, is determined. In quadrant 1, excess sebum and moisture is first removed from the finger tips with the help of a clean cloth. In quadrant 2, fingertip is first wiped around the nose or forehead to create excess sebum. Quadrant 3 and 4 were used to compare the details between untreated and dusted fingerprint residues.
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)
In conclusion the relationship between the properties of skin and friction skin impressions is that without these characteristics or capabilities fingerprints wouldn’t exist. The
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
Porous surfaces are which the evidence is absorbed into the material. Porous evidence can be best described as a sponge that absorbs residue; such as, paper, checks, currency, unfinished wood, cardboard, rugs, clothing, and other similar material. These items do not require treatment by the crime scene investigators. An investigator should never try to obtain or lift prints from porous items of evidence; instead they should be taken into a laboratory for the proper procedures to take place for this matter. The forensic team must always handle this type of evidence with caution and using clean gloves. There is a small probability of destroying latent prints on porous evidence but there is a greater chance that additional latents might come
Word choice is perhaps one of the most important aspects of writing in the forensic science discipline. “Fingerprint examiners often argue that because friction ridge formation is induced by the stresses and strains experienced by the foetus in utero, which are random and infinite, it is likely that they subsequently produce a random, infinite variety of friction ridge patterns.” (Page, 2011). In the forensic science discipline, there are keywords that have to be known to have a professional and scientific style of writing the will be acceptable. A forensic scientist cannot write a report about the fingerprints of a subject and say that the has a unique pattern of bumps on their fingers. They have to use keywords such as friction ridge patterns, for their report to
Latent print work in cases involving such cases, for example, murder cases is one of the processes that is used by the investigators of a crime in the course of trying to unravel the culprits that were involved in the murder. In cases where the identity of the victim is not clear or is not determined immediately, latent impressions could also be used to bring to light the identity of the victim. Latent impression about forensic science could be defined as any accidental or chance impressions that might have been left as a result of friction ridge skin on something like a surface. The impressions that have been left could be visible or sometimes invisible during the time that they are deposited on the surfaces although the word latent is used to refer to invincible. The skin contains some deposits of oil as well as perspiration that is responsible for coating the surface.
Latent fingerprints are mostly impressions left at a scene that are not noticeable to the naked eye; they are also one of three classifications of fingerprints that can be found at the scene of a crime or anywhere else. Latent prints
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.
One of the most important purposes of physical evidence is to establish the identity of a suspect or victim. Some of the most valuable clues at a crime scene are fingerprints. "Processing a crime scene" is a long, tedious process that involves focused documentation of the conditions at the scene and the collection of any physical evidence that could possibly shed light on what happened and point to who did it.
The purpose of this experiment was to determine how different surface temperatures affect the appearance of latent finger prints. In order to run this experiment, thirty Standard Select Carolina Microscope Slides were wiped with rinsed with tap water then blotted dry with Kimwipes. Ten microscope slides were chilled to negative nineteen degrees Celsius, ten others were left out, resulting in a temperature of twenty-three degrees Celsius, and another ten were incubated to thirty-seven degrees Celsius. After five minutes the slides were removed from the freezer and a thumb print, using Alex’s left thumb, was placed on each slide. Alex’s thumb was used as a general representation of the public, as while no fingerprints can be the exact same;
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.