Latent Fingerprints Lab Report

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.

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

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

On the morning of May 6, 2004 Attorney Brandon Mayfield was arrested by the FBI at his office in Portland Oregon for being suspected of involvement in the “March 11, 2004 bombings of four commuter trains in Madrid, Spain that killed 191 people and injured over 2,000 others” due to a fingerprint found on a plastic bag (Sherrer). Fingerprint analysis “has been used to identify criminals for more than one hundred years. The process begins with a deposited, or ‘latent,’ print found at the scene of the crime” (“Fingerprint Analysis”). If the print is detailed enough, fingerprint analysts can visually compare the print from the crime scene to the fingerprints of a suspect. They compare “qualities such as the general shape of the prints, the shape and depth of the ridges in the print, and the length of each ridge” (“Fingerprint Analysis”). It has been said time and time again that no two people’s fingerprints are exactly alike, and that if the latent print and the suspect’s print match, the print must be theirs. This assertion, however, “is not based on any studies, research, or analysis. In other words, there is no scientific basis for the belief that fingerprints are unique to each person” (“Fingerprint Analysis”). The main problem with fingerprint analysis, as with bite mark analysis, is its subjectivity. Instead of “relying on tested scientific methods, the process is mostly based on the subjective beliefs of the analyst” (“Fingerprint Analysis”). This basically means that “because of the lack of validity of the testing and retesting process” and the “overall subjectivity of the process indicates that the analyst is not truly absolutely certain of anything – except the fact that he or she truly believes a match” (“Fingerprint Analysis”). In Brandon Mayfield’s case, the print in question “had been positively identified as Mayfield’s by three highly qualified

When comparing

The first 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.

For processing fingerprints, forensic technicians plac lifting tape on the print. Then they carefully flatten the tape and slowly peel the tape off of the surface, hence lifting the print. After the print is lifted, forensic technicians will than seal the lifted print to keep it from being contaminated.

This compares how the

During the 19th century the study of fingerprints had emerged. The past few centuries we have had numerous developments in fingerprinting. A lot of people give this credit to Francis Galton, who conducted the first study of fingerprint patterns. Galton’s research showed that no two fingerprints are identical; his theory on fingerprints changed the world and the criminal justice system as a whole. Galton studied numerous fingerprints and came to the conclusion that not even identical twins will have the same fingerprints. This finding helped build the justice system and forensic science as we all once knew it. According to Galton fingerprint impressions fall into three different categories, they are loop, arch, and whorl. Another fingerprint known as latent print is a fingerprint that is formed by sweat. This type of fingerprint is not visible to the naked eye; usually a gray or black powder is used to pick up latent prints. Now that we know the three basic categories of fingerprinting, we must take a better look at how fingerprints are identified. We will look at some of the landmark cases that helped DNA become what it is today.

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;

As a crime scene fingerprint specialist you adhere to a variety of guidelines according to the department’s Standard Operating Procedures. When you come initially onto the murder scene, it has already been, cleared, secured, photographed, measured, sketched, and notes taken on the location of the evidence. This actually makes fingerprinting easier to accomplish correctly because the majority of difficult tasks associated with a murder scene has been completed. All non-movable items should be processed on scene using black magnetic powder, gray powder, or black powder. After using the chosen powder, utilize a camera (both in color and black and white), prior to lifting any prints to ensure that all prints are recorded encase destroyed during

Fingerprints have been used for a very long time, as far back as 3,000 years ago in China as identification. The use of ancient fingerprints are not the same techniques we use today. In 1880, a man by the name of Henry Fauld, “a Scottish physician working in a hospital in Japan, published his own views on the potential application of fingerprinting to personal identification” (Saferstein, 2016, pg. 164). He suggested that the skin patterns could be important for the identification of criminals. After comparing different fingerprints, he began to realize that each print looked remarkably different. Fauld believed that fingerprints could be used as evidence and suggested the proposal to a fingerprint testing center, but the offer was rejected. Years later, the first prosecution fingerprints were used in the year 1905 in London (Rotella, Abbott, & Gold, 2001). Ever since then fingerprints have been a valuable part of crime scene investigations and if present, it is almost guaranteed that the criminal will fit the crime. It has been a successful technique that has proved more success than any other piece of evidence.

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.

Polydimethylsiloxane is a silicone based polymer which is commonly used in huge flexible electronics applications due to its unique properties such as optically clear, inert to chemical compounds, and good mechanical strength when compared to the existing flexible substrate. PDMS are the most preferred substarte due to its ease of processing and its biocompatibility (Peterson et al. 2005; Ostuni et al. 2000; De Silva et al.2004; Tan et al. 2003; du Roure et al. 2005). (Abel L. Thangawng et al 2007). The mechanical strength of the PDMS is directly proportional to the amount of cross linking agent integrated into the polymer. Increasing the concentration of cross linker increases the mechanical strength of the PDMS and makes the PDMS to be less