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Use of technology in crime investigation
Writing about forensics entomology
Writing about forensics entomology
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Forensic entomology is most commonly used in suspicious criminal cases. P.C. White (2010) suggests that insects are responsive to certain stimuli and from this we are able to capture an insight into an insects contribution to crime solving. We can determine many different aspects of a case by the presence of different insects colonising a dead body, blowflies for example, are the first to approach the body when its fresh. This is due to their preference of food sources. Ultimately, I will explicitly focus on the relevance of a blowfly at a crime scene.
Blowflies can appear at the site of a decomposing corpse as quickly as ten minutes after the time of death. Once at the corpse, eggs are quickly deposited in natural orifices such as the eyes
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or mouth. The blowfly has such a predictable lifecycle that their presence at the corpse is extremely invaluable. This makes the Blowfly the best time since death indicator if the incident occurred over 72 hours ago. The Blowfly larvae go through three stages of growth, known as instars. "During the second and third instar, they form larval masses and feed voraciously on the soft tissues of the body." (Cooper and Cooper 2013 p.153). This means the corpse can be a matter of skin, bone and cartilage in roughly two weeks. During the prepupal period feeding comes to a halt and the larvae leave the corpse for a dry place to pupate. At this time, skin hardens and after about 24 days, due to the process of metamorphosis, the larva is now an adult. The Ruxton 'Jigsaw Murders' was the first case were forensic entomology was used in a successful way to identify the perpetrator of a crime. Two bodies were found in a stream outside Moffat, the two victims bodies were surgically taken apart to ensure their identification was protected. The bodies were wrapped in newspaper but the information on them was vital in solving the case. The newspapers were only distributed in two locations: Morecambe and Lancaster. During the investigation, samples of various maggots were sent to a laboratory at the University of Edinburgh. It was here that Dr Mearns identified the species of maggot as the blowfly. From here, further research was carried out and it was established the maggots were 12 - 14 days old, which gave the minimum time the bodies could have been left in the stream. The bodies were then identified as Mrs Isabella Ruxton and Mary Jane Rogerson. Dr Buck Ruxton was convicted of their murder with a substantial amount of evidence against him. The newspapers came from his place of residence whilst they were also dated the 19th of September, 5 days after the two victims were reported missing. Furthermore, the research done on the maggots gave a timescale of the murders and Ruxton was hanged in May the following year as punishment for his crimes.(Personal Communication) Blowflies are ectothermic so they rely on external sources of heat, and the predictability of their lifecycle is determined by the ambient environmental temperature.
In very hot and very cold temperatures, maggots cannot survive and certain environmental factors can inhibit their productivity and usefulness to a case. For example, in Winter there is far less insect activity and it may not be until Spring that blowflies are active on a corpse(Personal Communication). This limits the validity of the use of blowfly larvae in a case dramatically. Additionally, in Summer blowfly activity is much more rapid and as a result the body will decompose faster as conditions are more favorable(Personal Communication). This can also be problematic as valuable evidence may now be unidentifiable or completely lost. Drugs can also make very unreliable results when ingested by blowfly larvae. Drugs can speed up, slow down or stop the growth of larvae completely. Detection of drugs can only be found in the larvae themselves and not in the newly developed adult as it has now passed out of their system(Personal Communication). An example of this is cocaine, which speeds up development if the larvae and is the reason for the 'super maggot'. As this type of maggot is considerably bigger than those without the presence of cocaine, discrepancies in time of death are often encountered. However, this can be useful for identifying if certain drugs were present in the blood of a victim, either further …show more content…
advancing a case or maybe even solving it completely. "Insects are particularly attracted to wounds that have been inflicted prior to death..." (Jackson and Jackson 2011).
This is very useful in determining if a victim had multiple wounds before death or had just one fatal wound. If a wound had been inflicted perimortem it will bleed considerably more than if a wound was made after death. Due to this, blowflies are more attracted to the perimortem wound. An indication a perimortem wound has taken place is that a high number of blowfly larvae will be away from a natural orifice. In some cases of abuse and neglect, eggs can be laid in wound sites where the individual is not deceased. Myiasis is the disease in which rotting flesh becomes attractive to insects and they feed on living tissue(Personal Communication). Eventually infection spreads and the certain tissue dies. However, in cases of suspicious death myiasis can cause problems calculating the post mortem interval.
To conclude, the development and use of forensic entomology, especially the use of the blowfly, has benefited investigations into suspicious deaths dramatically. A highly predictable lifecycle makes it easy to determine an accurate post mortem interval and even though varying factors such as temperature and drugs can affect the reliability of the use of the blowfly present at a crime scene, it is clear forensic entomology is an important and highly successful asset in crime solving. Without the use of the blowfly, in particular, I feel we would be far worse off
when dealing with suspicious criminal cases.
A maggot found in the boot of Stafford’s car was found that matched the same one taken from the deceased body on the 26th September when she was found. The maggots were of same age and type.
To conduct the experiment, the beetles were massed, then attached to a petri dish with a 30 centimeter piece of dental floss. The beetle’s mass was the independent variable. Afterwards, the floss was tied to the beetle’s midsection with a slip knot. Then, the beetle was placed on a piece of fabric with the petri dish attached to it. As soon as the beetle was able to move with one paperclip inside the petri dish, more were added, one by one, until it could not move any further. After the beetle could not pull any more, the paperclips were massed and the results were recorded. The dependent variable was the mass that the beetles could pull. No control group was included in this experiment.
The crime scene was located in a deer hunting area in a meadow. There were several different types of trees and foliage surrounding the area where the skeletal remains were discovered. The...
Investigators can find clues from a murder through a number of different ways. Typically they find out how many times someone has been stabbed or however many blows they received. Through the count of the times the action had been performed they can come to an understanding of whatever hand the suspect was using. Other information can tell how the suspect was standing over their victim during the time of death. A common tool that forensic units use is the ultra violet or UV light. An 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)
When a death occurs suddenly, unexpectedly and from unnatural or unknown causes, a forensic scientist has the duty to gather and analyze evidence to determine whether the victim died from a previously undiagnosed disease or infection or from a homicide, suicide or accident (Lurigio, 2009). When considering suicide as the probable cause of death, we are looking at the act of intentionally killing oneself through one’s own effort or with the assistance of another (Sever, 2009). The resolution of the manner of death by a forensic pathologist as suicide is based on a series of factors which eliminate natural causes of death, homicide and accident (Geberth, 2013, p.55). The cause of death is also determined by the medical examiner in conjunction with the crime scene investigator; however, it can only be determined after a thorough investigation is concluded. Therefore, in the complicated process of doing a death investigation there are several mistakes that should be avoided, which are discussed in Geberth’s article, Seven Mistakes in Suicide Investigation (2013). Mistakes in doing any death investigation affect the integrity of the evidence in determining the cause of death and in its admissibility in court.
Richard Wilbur's recent poem 'Mayflies' reminds us that the American Romantic tradition that Robert Frost most famously brought into the 20th century has made it safely into the 21st. Like many of Frost's short lyric poems, 'Mayflies' describes one person's encounter with an ordinary but easily overlooked piece of nature'in this case, a cloud of mayflies spotted in a 'sombre forest'(l.1) rising over 'unseen pools'(l.2),'made surprisingly attractive and meaningful by the speaker's special scrutiny of it. The ultimate attraction of Wilbur's mayflies would appear to be the meaning he finds in them. This seems to be an unremittingly positive poem, even as it glimpses the dark subjects of human isolation and mortality, perhaps especially as it glimpses these subjects. In this way the poem may recall that most persistent criticism of Wilbur's work, that it is too optimistic, too safe. The poet-critic Randall Jarrell, though an early admirer of Wilbur, once wrote that 'he obsessively sees, and shows, the bright underside of every dark thing'?something Frost was never accused of (Jarrell 332). Yet, when we examine the poem closely, and in particular the series of comparisons by which Wilbur elevates his mayflies into the realm of beauty and truth, the poem concedes something less ?bright? or felicitous about what it finally calls its 'joyful . . . task' of poetic perception and representation (l.23).
Crime scenes are known to have many clues left behind. The obvious would be a the body or bodies, clothing, and sometimes even the murder weapon. While these are great way to solve a case there's another kind of evidence; trace evidence. Trace evidence are small pieces of evidence that are laying around a crime scene. There are many types of trace evidence some of them include metal filings, plastic fragments, gunshot residue, glass fragments, feathers, food stains, building materials, lubricants, fingernail scrapings, pollens and spores, cosmetics, chemicals, paper fibers and sawdust, human and animal hairs, plant and vegetable fibers, blood and other body fluids, asphalt or tar, vegetable fats and oils, dusts and other airborne particles, insulation, textile fibers, soot, soils and mineral grains, and explosive residues. Although these are the most common found elements, they are not the only ones. The Trace Evidence Unit is known to examine the largest variety of evidence types and used the biggest range of analytical methods of any unit. materials are compared with standards or knowns samples to determine whether or not they share any common characteristics. In this paper I will discuss the different kinds of trace evidence and how crime scene investigaros use it to solve cases and convict criminal.
results of the forensic anthropology. For instance, if a crime is committed at a certain scene,
The term forensic toxicology is defined as examination of all aspects of toxicity that may have legal implications (James & Nordby, 2009 p. 61). In the past, poisoning was one of the most popular forms of murder. There are countless natural substances in the world that when ingested into the body in high doses, can become lethal to the human body. What made this form of murder so famous is that most poisons mimic common medical diseases, leading physicians to believe a victim died of natural causes (Ramsland, n.d.). Aside from murder, this forensic discipline is also essential for determining accidental deaths and suicides.
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
Forensic Science, recognized as Forensics, is the solicitation of science to law to understand evidences for crime investigation. Forensic scientists are investigators that collect evidences at the crime scene and analyse it uses technology to reveal scientific evidence in a range of fields. Physical evidence are included things that can be seen, whether with the naked eye or through the use of magnification or other analytical tools. Some of this evidence is categorized as impression evidence2.In this report I’ll determine the areas of forensic science that are relevant to particular investigation and setting out in what method the forensic science procedures I have recognized that would be useful for the particular crime scene.
Forensic entomology is the study of insects and arthropods and their relation to a criminal investigation. Forensic entomology can determine the postmortem interval (PMI) or how long since the descendants’ death, whether the body has been moved since expiring, and what injuries may have been sustained (Ryan, 2011). When decomposition begins, insects establish a colony to lay eggs on the remains; these eggs will hatch into larvae that will eat the human organs and tissues. Forensic entomologists can determine the specific insects present in the body and estimate how long a body has been left exposed by examining the stage of development of the fly larvae; however, these findings are not always plausible. The fly larvae look and act different at each stage of development. The time required for stage development is not only affected by environmental influences such as geographical location, climate, and weather conditions, but also by type of insect. The forensic entomologist must consider these conditions when estimating the postmortem interval. Knowledge of insects, their life cycles, and their habits make entomological evidence a priceless tool for an investigation. Forensic entomology has proved its significance in a number of cases; though circumstances such as weather, temperature, and time of year clearly affect the development of insect infestation, and the expert must keep these in the forefront of his/her mind (Innes, 2000).
The Bt spores then leak from the gut and germinate in the insect, causing death within a few days.
The firefly is sometimes referred to as a “lightening bug.” There are about 2,000 firefly species; for the most part they live in warm but humid environments. Fireflies are neither flies nor bugs; they are actually part of the beetle family. Fireflies are from the Animalia kingdom, and are of the Lampyridae family. Fireflies hibernate over winter by burrowing underground, under water or settle under the bark of a tree some can live for several years by hibernating as larva during the winter.
Many of us enjoy watching crime scene investigation shows, but in the criminal justice system forensic investigation is an essential field that requires upright observations and a prodigious interpretation. Under forensics, it is difficult to blame someone without scientific data. For that reason, Larry K. Gaines author of the textbook Criminal Justice in Action explains the importance of Blood Spatter Analysis. Specialist can learn a great deal about violent crime by examining where blood landed at the scene, the size and consistency of drops, and the pattern of blood spatter (Gaines, 2011). Consequently, an article of the Blood Spatter Analysis will be used to explain the research methodology the author uses to proceed certain investigations.