In crime scene investigations, hair is one of the most common types of evidence encountered. Hair evidence is picked up at the scene, and usually collected from several different areas on the body. Through hair analysis, we can determine if the source is human or animal, and what race the source is a member of. When analyzing hair, the color and structure is the main view of focus and is determined through microscopic magnification. Today hair evidence has played a significant role in criminal investigations and has helped solved many cases.
Hair analysis begins with the identification phase. First, the hair has to be determined if it is human or not. Human hair is classified into two main categories: vellus hair and terminal hair. Vellus hair is very fine and hard to see and can be found all over the body. Terminal hair is the hair you frequently see in eyebrows, beards, head hair, pubic hair, arm hair, and leg hair. Since there are so many different types of animals, non-human hair has several different characteristics. The four classifications that generally apply to forensic investigations are: fur or wool, vibrissa or tactile, bristles, and other hairs such as manes or tails on horses. Animal hairs can be distinguished from human hairs in numerous ways. The medulla is a tubular structure that runs down the middle of the hair. It can be thick or thin and continuous or discontinuous. Animal medullas’ are usually thicker, where as human hairs have fragmented, inconsistent medullas, or sometimes no medulla at all. Another way to distinguish animal hair from human hair is color. In human hair there are only three pigments found: yellow, black, and brown. Human hair is colored more evenly. In animal hairs, different sections of...
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...a to go insane. He shoved a handkerchief into her mouth, tied her hands with cord, and raped her. Afterward, he tied her pajama jacket around her throat and dragged her to the bathroom, where he dumped her into the bathtub. When he left he said that she was still breathing. He was found guilty and executed on January 22, 1937.
Without the use of hair analysis, the connection between John Fiorenza and the case most likely would have never been found. With today’s technology, hair analysis is becoming more common in catching killers. Hair analysis can demonstrate that there may be an association between a suspect and a crime scene, or the suspect and the victim. It can also conclude that the hair came from one person, which can exclude other people from a crime. As technology advances in the future, hair analysis will be a key forensic technique when solving crimes.
Other evidence located within the grave consisted of a generic watch, two cigarette butts, a button, a washer and a shell casing. All of these could be analysed for finger prints and DNA. The cigarette butts would also show a serial number indicating the brand (shown in Figure 3), which can be useful if it is found a victim or offender smokes a particular type of cigarette.
The crime he committed was terrible and obviously something that could only be done with someone who lacks any good intentions. His behavior during the his trial also showed the extent of his maliciousness. He half-heartedly attempted to defend himself by claiming the prosecutors were using false evidence and that, according the records of the United States District Court for the Western District of Texas, “Nobles concludes that he was denied the fundamentally fair and impartial trial guaranteed him by the Due Process Clause of the Fifth Amendment”. He put very little effort into defending himself during the trial and was quickly sentenced to death. In the early years of his time in prison he was far from the ideal prisoner. Earle presents how “He once broke away from guards while returning to his cell from the exercise yard and climbed the exposed pipes and bars in the cell block, kicking down television sets suspended outside on the bottom tier.” and on another occasion he cut himself just so he could hit an officer while they were attending to him before he passed out. This kind of behavior was completely eradicated long before he was executed, procuring him the respect of the prison
Just because a hair is found at the scene doesn’t mean that it belongs to the perpetrator. It is important to take Locard’s Principle into account, “The microscopic debris that cover our bodies are the mute witnesses... of all our movements and all our encounters.” (Robertson, 7.2) When you come into contact with something or someone, there is always a transfer, even if it isn’t noticeable. There are different types of transferring, primary and secondary. Primary transfer is when something transfers from you to another source. When someone comes into contact with that source, there is a chance that your hair or fiber transfers onto the other person. This is secondary transfer. Because humans shed hair frequently, it is easy for hair to go through secondary transfer and end up somewhere that the individual had never been. Hair can remain on a source for a couple hours without being transferred and it does not break down very easily, so this can remain in place for a long time. (Robertson,
the DNA from the roots of the hair. The replicated DNA samples were then placed into the
A common tool that forensic units use is the ultra violet or UV light. Ultra violet light can detect different areas that contain blood that might not be able to be seen in other conditions. Another common tool is the blood reagent test that forensics use on scene. These tests determine if the blood is human or animal. Renee Blake - "The 'Renee Blake'" There are different types of bloodstain patterns that give a sense of what happened at the scene.
The blood of the unknown person became apparent through comparing the blood type found at the crime scene with the contrasting blood types of the suspects. The blood identified at the crime scene could have possibly belonged to Anna Garcia or Erica Piedmont. This observation was based on the information that the blood type found at the crime scene was type A and these two individuals are the only ones that carry that specific type. In similarity, a microscopic photography was taken of the unknown hair follicle found at the crime scene. Then hair samples were taken from the potential suspects, and the victim. These findings were then compared. This was done by looking at each individuals hair follicles and comparing it with the unknown one. By looking at the similarities and differences in medulla diameter, the discovery of the unknown hair follicle became established that it belonged to Anna Garcia. Further examination resulted in the analyzation of a shoe print found at the crime scene. Shoe patterns and sizes were taken from each suspect, including the victims. They were then identified and compared to the one found at the crime scene. By looking at the distinct pattern, size, and the fact that both shoes were a Columbia brand sneaker it became obvious that the shoe print was extremely similar to Anna’s shoe design. Through this found evidence it became
These hairs may be of evidentiary value to show contact between two people. With an adequate hair standard, a trace chemist will be able to microscopically compare an unknown hair to a standard collection and determine if the unknown hair could have come from the individual under investigation. Hair comparisons can not identify hair as coming from one individual to the exclusion of anyone else. DNA testing can strengthen any possible association with the hairs." - Locard.... ... middle of paper ... ...
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
... tested hairs and other parts for DNA and concluded that they fit into our family tree. “ Those hair samples that could not be identified as known animal or human were subsequently screened using DNA testing, beginning with sequencing of mitochondrial DNA followed by sequencing nuclear DNA to determine where these individuals fit in the tree of life” (Ketchum 2013).
Once a crime has been committed the most important item to recover is any type of evidence left at the scene. If the suspect left any Deoxyribonucleic acid (DNA) at the crime scene, he could then be linked to the crime and eventually charged. A suspect’s DNA can be recovered if the suspect leaves a sample of his or her DNA at the crime scene. However, this method was not always used to track down a suspect. Not too long ago, detectives used to use bite marks, blood stain detection, blood grouping as the primary tool to identify a suspect. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique it has been a la...
In today’s time, modern Crime Scene Investigation has increased rapidly. From throughout the late 1900’s and in the early 2000’s (Taylor 1). For all of the evidence that they find, a solid foundation has formed over the thousands of years of Crime Scene
Before the 1980s, courts relied on testimony and eyewitness accounts as a main source of evidence. Notoriously unreliable, these techniques have since faded away to the stunning reliability of DNA forensics. In 1984, British geneticist Alec Jeffreys of the University of Leicester discovered an interesting new marker in the human genome. Most DNA information is the same in every human, but the junk code between genes is unique to every person. Junk DNA used for investigative purposes can be found in blood, saliva, perspiration, sexual fluid, skin tissue, bone marrow, dental pulp, and hair follicles (Butler, 2011). By analyzing this junk code, Jeffreys found certain sequences of 10 to 100 base pairs repeated multiple times. These tandem repeats are also the same for all people, but the number of repetitions is highly variable. Before this discovery, a drop of blood at a crime scene could only reveal a person’s blood type, plus a few proteins unique to certain people. Now DNA forensics can expose a person’s gender, race, susceptibility to diseases, and even propensity for high aggression or drug abuse (Butler, 2011). More importantly, the certainty of DNA evidence is extremely powerful in court. Astounded at this technology’s almost perfect accuracy, the FBI changed the name of its Serology Unit to the DNA Analysis Unit in 1988 when they began accepting requests for DNA comparisons (Using DNA to Solve Crimes, 2014).
Just as insight into the mind of the artist may be gained by examining and comparing the progression of his work, so knowledge of the mind of the serial killer can be ascertained by an examination of his canvas: The murder scene. Forensic profiling is the attempt to do just that. An investigator tries to discern information about the killer based on the information at the crime scene, deducing information about the cause from the effect. This is not an exact science, and has been often likened to an art. It is the goal of this work to provide the reader with a basic understanding of the function and application of forensic psychology, as well as an explication of some of its strengths and weaknesses.
In here I will clarify each potential evidences of the crime and explain of the application of the identified forensic procedure to the facts of the case. One of the perpetrators cuts his hand when trying to drag of the witness in the crime scene. Thus, in this case blood stains would be the one of the potential evidence. The precipitin test might be applied to bloodstains in a numerous ways. It conduct...
Forensic science has now been recognized as an important part of the law enforcement team to help solve crimes and cold cases. The advances in technology are being used each day and we must continue to strive to develop better advances in this field. The recent discovery of using DNA in criminal cases has helped not only positively identify the suspect, but it has helped exonerate hundreds of innocent individuals. “With new advances in police technology and computer science, crime scene investigation and forensic science will only become more precise as we head into the future.” (Roufa, 2017) Forensic science and evidence helps law enforcement officials solve crimes through the collection, preservation and analysis of evidence. By having a mobile crime laboratory, the scene gets processed quicker and more efficiently. Forensic science will only grow in the future to be a benefit for the criminal justice