Identification of Finger Prints, Blood and DNA

denomination of riffle Prints, Blood and DNAINTRODUCTIONforensic science is astray utilize in the service of the justice system (Jackson). It has helped in work studys by providing important clues and evidences. The usage of forensics in solving crime cases is inevitable. Forensic sciences is utilise in various beas bid reproduceing, DNA profiling, blood malignment get holdion and many practic wholey(prenominal).From the early days of complicated body mea undisputablements to todays advanced(a) biometric devices, the acknowledgement of individuals by their bodies has been a mainstay of government and law enforcement. estimatorized databases wish well AFIS now make it possible to comp ar thousands, or in the case of the FBI, millions of finger publishs in minutes.With the advancements in DNA detecting mechanisms, blood stains in the scenes of crimes beat also pay off one of the most important evidences. After a homicide or an assault has been committed, police inv estigators usually find blood at the scene of the crime. This gives them clues as to what happened du make noise that incident. The bloods texture and shape and how it is distri yeted around the victim practically help investigators determine when and how the crime was committed. A number of techniques ease up been substantial for the identification of finger affects and blood stains in the crime scene.EVOLUTION IN reproduce TECHNIQUESIn the mid-1950s finger belief was through using the dangerous mercury-based white mill, a coarse graphite-based black pulverise and squirrel-hair brushes.With a burst of innovation concerning reproduce evidence as part of the crime investigation, ninhydrin trying was developed. This system is highly efficient on composing items, especially if the stock effect is added to fluorisol, which prevents authorship on the paper from smudging. Ninhydrin reacts with the amino acids in perspiration, producing red, brown, or purple imprints this is a most successful method of investigating check fraud.During the last decade, new(prenominal) techniques for discovering latent imprints concord been developed. These include Super Glue, physical developer, small-scale atom reagent, lasers, metal deposition, Sudan black, amido black, thermoplastic fingerprint powders and radioactive sulfur dioxide. Exceptional powders are available with greatly improved fingerprint brushes to help cans in fingerprinting. DFO is a recent improvement on ninhydrin, providing up to 300% more finger and palm imprints.One some other advancement in this domain is the use of photoluminescence. Fingerprint luminescence excitation initially used lasers, but filtered lamps are employed as well. This technology helps the forensic scientist to take a get a line of the fingerprints outright at the crime scene.Computers are now used throughout the world for maintaining and searching files of imprints and fingerprints of offenders found at crime scenes. C omputer searches of crime scene imprints provide excellent results. The computer blasts through murder collections at fantastic speed, possibly scanning millions of digits, but in that location is no promise that the offender who make the imprints is not in the collection if identification is not made. Bio-metrics especially fingerprints has become one of the main areas of research.EVOLUTION IN BLOOD STAIN DETECTION TECHNIQUESBlood is one of the most greens physical evidences which is present in murder cases, accidents and violent crime investigations. A determination must be made if it really is blood. Eventhough there have been various sieves to detect the front line of blood, the widely used scrutinys are Kastle-Meyer test and the Luminol testify.Luminol is first activated with an oxidant, usually a solution of hydrogen hydrogen peroxide and a hydroxide salt in water. Then, in the presence of a protein present in blood called hemoglobin, the hydrogen peroxide decomposes to form group O and water. Luminol reacts with the hydroxide salt, leading to the formation of a dianion. The oxygen produced from the hydrogen peroxide then reacts with the luminol dianion. This chemical reaction produces an organic peroxide, which is precise unstable and hence it immediately decomposes with loss of nitrogen to produce 3-aminophthalic acid (3- APA) in an excited state. As 3-APA relaxes, it releases a visible blue light. Luminol is sensitive to the presence of extremely small tot ups of blood. It can detect bloodstains that have been diluted up to 300,000 times.The KM Test is a presumptive test which is used to check the presence of hemoglobin using phenolphthaleins color reposition in the presence of oxygen. abridgment AND interpretation OF DATAFINGER bell ringerING surmiseFingerprints often leave residues of oils in the shape of the friction ridges. However, the friction ridge skin does not discharge oils. Some fingerprints will leave a residue of amino aci ds and other compounds. These principles make dusting techniques to develop fingerprints. (Finger print Powder- Wikipedia the free encyclopedia)CLASSIFICATION OF FINGER sign PATTERNSThe following table contains the finger print patterns for the fingers and toesRight Hand feelWhorlIndex FingerWhorl middle Finger draw inRing FingerWhorlSmall FingerWhorlleft field HandThumb ArchIndex Finger WhorlMiddle Finger LoopRing Finger LoopSmall Finger LoopThe toe prints are all arch expect for the ring toe in the right leg which is whorl.The fingerprints using sign keep ones shoulder to the wheel for the fingers and toes can be found in Annex C.DIFFERENCE IN PATTERNS BETWEEN FINGERSThe pattern in all the fingers except the left flip out is whorl. This might be the case because the environmental factors within the fetus would have been kindred for the fingers and hence there is not much change in the pattern between the fingers.DIFFERENCE BETWEEN HANDS AND TOESThe finger prints in the hands are very lax to identify when compared to the toes. This is because the fingers are whacking enough for us to deposit the prints properly. However, the legs are small and since we dont use them like fingers it is very difficult to deposit it even while using the ink pad. Since the whole bodys pressure is on the toe, too much of pressure was utilize on the paper by it. and so the prints werent stimulate.DIFFERENCE BETWEEN ageing AND NEW PRINTSThe hoary prints are not as bright as the new prints. The old print gets exposed to the atmosphere and hence they react with the air. Hence split of the print vanish. Hence it is not as homely as the new print. However, the old prints is good enough for matching 16 positions on the finger print and thus easy to the catch the criminal.The old big toe prints deposited wasnt seen when developed by both the magnetic powder as well as the black powder. This is because the print wasnt deposited properly. Too much of sweat on the print made t he prints to be smudged when the powders where used to detect their presence. Hence the prints were seen very faintly.DIFFERENCE BETWEEN METHODOLOGIESThe black powder had to be done very carefully since two much of powder made the finger prints to smudge. The magnetic powder was easy in a modality because excess magnetic powder could be removed easily. However, the dusting had to be done slowly and such that that the brush wasnt too close to the finger print in order to get the print properly. The ninhydrin test was very easy because we didnt have much to do for it. However, many of my friends prints were pale. This might have been because they didnt pay enough pressure on their papers when they deposited the prints.Since I had applied so much moisture, the finger prints smudged badly and the prints werent clean-living. Hence I had to repeat the butt against again. However, the next I exerted too much pressure on the paper which made the fingers to sweat too much leading to smud ging. Also the amount of time given to register the finger prints was too less.Out of the three methodologies used in this lab I find the ninhydrin solution test to be the most efficient one. This is because for because the human influence in this method was very less. Since we were beginners in this lab, we didnt have a proper idea of how much powder had to be used for these methods. thereof I prefer the ninhydrin solution method for fingerprinting especially for beginners.FINGER PRINT LIFTINGThe dusting for finger printing lifting was done using the magnetic powder since excess powder could be easily taken away. However, when I lifted it the first time, a lot of air bubbles where formed which made half of the finger prints to vanish. Also since I had not given enough time for my finger prints to settle the prints werent clear when dusting.Hence I tried to avoid these when I lifted the indorse time. I pressed gently and allowed the prints and gave some time so that the prints to settle. piece of music using the tape I made sure there were no bubbles. Hence I was able to lift a proper print of my right thumb finger using the lifter.IDENTIFICATION OF BLOOD STAINSTHEORYThe Kastle-Meyer test is a forensic presumptive test which is used to examine if the dried stains in a violent crime scene is peaceful of blood. The test is based on the peroxide-mediated oxidation of reduced phenolphthalein. In this reaction the heme molecule acts as a catalyst.The chemical indicator used in this test is phenolphthalein C20H14O4, a common acid-base indicator which turns pink, in raw material solutions with a pH of approximately 8 or higher.. Phenolphthalein, a clear dye, immediately turns pink if oxidized by hemoglobin and hydrogen peroxide. on that point are three reagents involved in this test. To increase the sensitivity of the test the reagent, Methyl or Ethyl alcohol is used. It does this by cleaning up the area in and around the bloodstain to better expose the hemoglob in. Phenolphthalein, the second reagent acts as a color indicator. This solution when oxidized (exposed to oxygen), turns pink. Hydrogen Peroxide is the 3% form typically found in drugstores. Hydrogen peroxide is basically water with an extra oxygen atom attached to it. These chemical reactions are set ahead stated using the following equationsThis test is nondestructive to the taste. Hence the exemplar can be kept and used in further tests at the lab. This test has the uniform reaction with human blood and living creature blood. So, further investigation is required to determine whether it is human or animal blood.ANALYSISThe blood stain dark pink instantly afterwards adding all the three reagents stating the presence of blood.When the reagents where added to copper powder, it turned pink even forwards the addition of the hydrogen peroxide showing giving a ill-judged result . Thus it is vitally important to add the reagent first, then anticipate a few seconds, then add t he hydrogen peroxide.K and so onup didnt change at all showing the absence of hemoglobin. Whereas, cabbage solution turned yellow.Beetroot and ribena solutions turned colourless due to their neutral nature with very very slight pink tinge occurring due to their natural colour.Hence except for copper there werent any false substantiating tests in the samples which were recognized.LIMITATIONSEventough Kastle-Meyer test can detect blood upto dilutions of 1107, there are many limitations for this test. In the presence of vegetable peroxidases, like in horseradish, broccoli, cauliflower, etc. the test gives a false peremptory result. Oxidizing species present in the sample also causes this test to fail. (Kastle-Meyer testLimitations)For example when this test was performed for copper powder the Kastle-Meyer reagent turned pink even before hydrogen peroxide was added to it. Thus it is very much important that we wait for a few seconds after the reagent is added and then only we need to add hydrogen peroxide.The Kastle-Meyer test gives overbearing results to both human blood as well as animal blood. In general, it gives a positive result to all hemoglobin containing blood.. In order to ensure that the blood is really from a human species, a confirmatory test such as the Ouchterlony Test is performed. (Kastle-Meyer testLimitations)In short, color catalytic tests are very sensitive in nature. The prejudicious results from these tests show that these samples do not hemoglobin and so it is not blood. However, the positive results need not be correct in all cases. It is remarkable to mention here that false positive tests occur due to the presence of a reducing agents, animal blood, peroxidases and many more. (Kastle-Meyer testLimitations)FINGER PRINT PATTERNS IN IDENTICAL TWINSWhen a fertilized egg splits into two, it leads to a breeding of two embryos. This leads to the development of Identical twin. Since the twins are formed from the same egg, their DNA is iden tical.The interactions between the environment in the fetus and the genes, plays an important manipulation in the fingerprints and the appearance of a person. The environmental factors include blood pressure, nutrition, etc. ( match Fingerprints Identical Twins and fingerprints) The genes thus play an important role in depicting the fingerprint patterns in humans. The skin of the finger is in fall into place with various parts of the fetus and anionic fluids in the uterus. The interactions between the fingers and these parts changes due to the movement of the fetus and the mother. Thus this microenvironment plays an important role in the details of the fingerprint patterns. (Why Identical Twins have Di)Though there are only minimal changes in the environment, the differentiating cells make the differences in the fingerprint pattern to be seen evidently. All these reasons make fingerprint patterns in the twins to be different. This also makes fingerprints between the finger and the toes from being the same. (Why Identical Twins have Di)Eventhough after birth, identical twins just look the same they also have a few physical differences for e.g. moles which help in distinguishing one from the other. These physical differences amplify day by day and become greatly evident.CONCLUSIONFingerprinting by dusting and ninhydrin solutions help in lifting them properly. It makes sure that none of the fingerprints in the crime scene is unnoticed. However, it is important to note that these techniques should be done only by people who are very experienced.Kastle-Meyer test helps in identification of blood stains but it also gives false positive tests. Hence the samples should be analyzed once again to check the presence of blood in it.The lab was very enriching and gave a true picture of what is done by forensic scientists at the crime scene.