One of the most common methods for discovering and collecting latent fingerprints is by dusting a smooth or nonporous surface with fingerprint powder (black granular, aluminum flake, black magnetic, etc.). If any prints appear, they are photographed as mentioned above and then lifted from the surface with clear adhesive tape. The lifting tape is then placed on a latent lift card to preserve the print.
However, fingerprint powders can contaminate the evidence and ruin the opportunity to perform other techniques that could turn up a hidden print or additional information. Therefore, investigators may examine the area with an alternate light source or apply cyanoacrylate (super glue) before using powders.
Alternate Light Source (ALS): It is
The purpose for this lab was to use aluminum from a soda can to form a chemical compound known as hydrated potassium aluminum sulfate. In the lab aluminum waste were dissolved in KOH or potassium sulfide to form a complex alum. The solution was then filtered through gravity filtration to remove any solid material. 25 mLs of sulfuric acid was then added while gently boiling the solution resulting in crystals forming after cooling in an ice bath. The product was then collected and filter through vacuum filtration. Lastly, crystals were collected and weighed on a scale.
Forensic Science Introduction: Someone in a restaurant has suddenly fallen ill and a mystery powder has been discovered with the victim. As the chief investigator, your duty is to identify the mystery substance through a lab. In this lab, it will consist of five known compounds and one unknown compound. Your job is to distinguish which one out of the five substances is the mystery powder. To figure out the mystery matter you will have to compare their physical and chemical properties and match them with the appropriate compound.
Next we will discuss the processes used when dealing with latent prints. First I will discuss the analysis of a latent print. So first when a latent print is sent to the lab who conducts the analysis? The forensic analysis is he person that conducts the analysis, or a fingerprint technician or even a police officer. Bu...
Another discrepancy between actual forensics and how it is portrayed in the media is the availability of information in databases. There is only a small percentage of the entire population’s fingerprints or DNA samples stored within databases such as the Integrated Automated Fingerprint Identification System (IAFIS). This makes finding a match between a DNA sample or fingerprint difficult, as a match would only be found if the person’s information was already stored within the database. If there is no match previously stored in a database, the fingerprint or DNA sample could be potentially rendered useless within a trial. Typically, in order to perform an analysis, investigators must already have a suspect in mind and request a DNA or fingerprint sample from him or her. If the suspect does not want to provide one however, the sample collected as evidence may not count as valid. The CSI effect creates an idealized image that all crimes can be solved with a hair or drop of blood, but this is not always the case in real life.
Contextual information also affects the human comparative part of fingerprint analysis, in ways that alter the matching of the same fingerprints, years apart; however, when contextual information is provided, it actually helps 20% of forensic technicians, but that still leaves 80% hindered by contextual information (Dror et al, 2006). Contextual information affects the psychological aspects of perception and problem-solving, in a way that can obscure information that does not support the context, and it can even affect how forensic technician’s view and handle forensic evidence (Bernstein et al, 2013). However, there are some advantages of contextual information, because it can give the forensic division a mental shortcut, saving time and money; however, these shortcuts lead to inaccurate and biased conclusions. This essay has shown that contextual information creates erroneous mistakes and prejudiced results in forensic investigations. A possible way to remove the negative effects of contextual information is to have the forensic technicians, not know the context of the crime so that they do not
passing of death from the dying deer to the sheriff who shot him for sport.
The criminal justice system has changed a lot since the good old days of the Wild West when pretty much anything was legal. Criminals were dealt with in any fashion the law enforcement saw fit. The science of catching criminals has evolved since these days. We are better at catching criminals than ever and we owe this advancement to forensic science. The development of forensic science has given us the important techniques of fingerprinting and DNA analysis. We can use these techniques to catch criminals, prove people's innocence, and keep track of inmates after they have been paroled. There are many different ways of solving crimes using forensic evidence. One of these ways is using blood spatter analysis; this is where the distribution and pattern of bloodstains is studied to find the nature of the event that caused the blood spatter. Many things go into the determination of the cause including: the effects of various types of physical forces on blood, the interaction between blood and the surfaces on which it falls, the location of the person shedding the blood, the location and actions of the assailant, and the movement of them both during the incident. Another common type of forensic evidence is trace evidence. This is commonly recovered from any number of items at a crime scene. These items can include carpet fibers, clothing fibers, or hair found in or around the crime scene. Hairs recovered from crime scenes can be used as an important source of DNA. Examination of material recovered from a victim's or suspect's clothing can allow association to be made between the victim and other people, places, or things involved in the investigation. DNA analysis is the most important part of forensic science. DNA evidence can come in many forms at the crime scene. Some of these forms include hair; bodily fluids recovered at the crime scene or on the victim's body, skin under the victim's fingernails, blood, and many others. This DNA can be the basis of someone's guilt or innocence; it has decided many cases in the twentieth century. As the times continue to change and the criminals get smarter we will always need to find new ways to catch them. Forensic science is the most advanced method yet, but is only the beginning. As the field of science grows so will the abilities of the
The three different main types of fingerprints are Loops, Arches, and Whorls (Jackson 1). Henry Faulds is known as the Father of Fingerprints and developing fingerprints (Jackson 1). His discovery of fingerprints has made a huge impact not only in his time but, in Modern Crime Scene Investigation (Jackson 1). Without fingerprinting, it would be very difficult to convict criminals of crimes and very hard to try to process information. Crime Scene Investigators make a huge impact in Forensic Science. We need CSI workers, without them people could only imagine what crime would be like not only in our community, but in our
The easiest way to figure out who was at the crime scene is by taking fingerprints. Good impressions such as fingerprints can be the most valuable pieces of evidence in a forensic investigation. Impressions help link a person to a crime scene or crime as well can provide information on any weapon that could've been used at the scene. An educated technician would compare and search fingerprints manually and on AFIS computer system for classification, comparison and identification. "Analyzing evidence is not a quick or simple process.
one may assume that a detailed investigation of William’s bedroom began before a search warrant was obtained or consent to search was given. Therefore, when crime scene investigators began to process William’s bedroom, any evidence found, including the bloody fingerprint that was not in plain sight but developed using an amino acid stain and an argon laser, would not be admissible in court.
Preview of main points: Now I am going to take you through the process of identifying, collecting and analyzing fingerprints.
...A. Maria, Ruth M. Robin. (2009). Latent prints: a perspective on the state of the science. Forensic Science Communications. 11.4.
Throughout our time here on Earth, we have probably had one or two people tell us to “live in the moment” and to quit worrying about the things we cannot control. The fictitious story, “Powder”, written by Tobias Wolff, exemplifies what this is all about by using a young, conservative, and often times controlling boy in contrast to his older, more fearless father. According to the short story, the boy was someone who “kept all of his clothes on numbered hangers to improve proper rotation and would ask his teacher for homework in advance”, whereas his father flew by the seat of his pants, driving in more dangerous weather conditions, often times breaking the law, and sneaking behind his wife’s back to attend concerts. However, it was on the way back home from a ski trip, that the boy learned from his father the importance of living in the moment, letting go of his perfectionist attitude, and being a bit
Physical evidence is additionally important in every criminal investigation because too often witness accounts are sometimes biased or unreliable. Physical evidence such as trace evidence, DNA, and fingerprints may objectively attach one or more persons to a victim or suspect to a crime. Favorably, physical evidence can also demonstrate inestimable for exonerating an innocent suspect. Laboratory members and criminal investigators should perform together to resolve the biggest portion of evidence to institute the right suspect for a strong prosecution. Willingly, investigation officers should aggressively contact laboratory personnel when questions arise about the cases because DNA evidence is sensitive.
...ooth it over the fingerprint. I hope that the police can find the match fingerprint as soon as possible to catch the bad people.