Evidences left at scene: Bloodstains (Injured hand), Oil (Leaking), Torch (Dropped), Tracks (Car tyre), Fingerprints (Did not use black gloves), Clipped gate (Car crashed into gate)
Evidences taken away: Jewellery
Suggestions for forensic scientists:
Test the bloodstain for DNA of the criminal
Trace the path left by the oil leak and car tracks
Check for fingerprints on the torch
Check the colour of the car paint left on the gate and match it with the car of the suspected criminal
Graded Activity 2: Avatar making and description writing
Picture of myself:
Avatar of myself:
Picture of Daryl:
Avatar of Daryl:
Description of Daryl:
Skinny, Short, Rounded face, Mole on the right, Short spiky brown hair, White rectangular spectacles, Cute
Graded Activity 3: Skeleton measurements
1. Human Skeleton Model
Height: 160.0cm
Gender: Male
2. My Dimensions!
Height: 159.0cm
Gender: Male
3. Reasons for Discrepancies
Human error, and we may measure wrongly due to parallax error. Also, instruments used to measure may not be precise enough to take an accurate measurement. Furthermore, every human have different body structure and our heights might vary in the day and night.
4. Golden ratio
In mathematics and the arts, two quantities are in the golden ratio if the ratio of the sum of the quantities to the larger quantity is equal to the ratio of the larger quantity to the smaller one. The golden ratio is an irrational mathematical constant, approximately 1.61803398874989. Other names frequently used for the golden ratio are the golden section and golden mean. Other terms encountered include extreme and mean ratio, medial section, divine proportion, divine section, golden proportion, golden cut, golden number, and mean of Phidias. In this article the golden ratio is denoted by the Greek lowercase letter phi, while its reciprocal, is denoted by the uppercase variant Phi.
My body does not fit the golden ratio. The golden ratio is 1.618.
Feet to Naval: 101cm
Naval to head: 61cm
My ratio is 1.656.
5. The case of the middle aged woman
Age of woman: 70 years old ( 2011 – 1940 – 1)
Length of tibia: 33.5cm
Theoretical height: 33.5cm x 2.352 + 74.775cm = 153.567cm
Actual height after subtracting (Height decreases by 0.06cm per year after 30 years): 153.567 – (0.06 x 40) = 151.167 cm
Graded Activity 4: Fingerprints
Conclusion: The proportions of the different types of fingerprints are rather similar to the theoretical proportions of the different types of fingerprints. However, there is an overwhelming number of people with arches as compared to the theoretical proportions. this might be due to the fact that there is human error as we might not have printed the "entire" finger and examine it closely with special devices that the forensic scientists do, thus resulting in a discrepancy in the results.
Reflections
I feel that this forensic science module is very enriching and interesting. Through various exercises, I have learnt more about forensic science and how to apply it in our daily lives. In the process of analyzing graphs and charts, I have also learnt how to use some of the basic functions in excel, for example to plot a graph or a table and to tabulate the results given and I hope these skills can be put to better use in the future. Furthermore, through studying fingerprints and analyzing evidences, it has also definitely improved my critical thinking skills and made me a sharper person. Last but not least, this module has also taught me how to calculate our height in a different way and learn about the golden ratio. All in all, I find this module very interesting and I truly appreciated it. I hope that the school can have more of such modules for me to analyse different aspects of science.
Newspaper Article + Reflections
Plugging Holes in the Science of Forensics
It was time, the panel of experts said, to put more science in forensic science.
A report in February by a committee of the National Academy of Sciences found “serious problems” with much of the work performed by crime laboratories in the United States. Recent incidents of faulty evidence analysis — including the case of an Oregon lawyer who was arrested by the F.B.I. after the 2004 Madrid terrorist bombings based on fingerprint identification that turned out to be wrong — were just high-profile examples of wider deficiencies, the committee said. Crime labs were overworked, there were few certification programs for investigators and technicians, and the entire field suffered from a lack of oversight.
But perhaps the most damning conclusion was that many forensic disciplines — including analysis of fingerprints, bite marks and the striations and indentations left by a pry bar or a gun’s firing mechanism — were not grounded in the kind of rigorous, peer-reviewed research that is the hallmark of classic science. DNA analysis was an exception, the report noted, in that it had been studied extensively. But many other investigative tests, the report said, “have never been exposed to stringent scientific scrutiny.”
While some forensic experts took issue with that conclusion, many welcomed it. And some scientists are working on just the kind of research necessary to improve the field. They are refining software and studying human decision-making to improve an important aspect of much forensic science — the ability to recognize and compare patterns.
The report was “basically saying what many of us have been saying for a long time,” said Lawrence Kobilinsky, chairman of the department of sciences at John Jay College of Criminal Justice in New York. “There are a lot of areas in forensics that need improvement.”
Barry Fisher, a past president of the American Academy of Forensic Sciences and a former director of the crime laboratory at the Los Angeles County Sheriff’s Department, said he and others had been pushing for this kind of independent assessment for years. “There needs to be a demonstration that this stuff is reliable,” he said.
It’s not that there hasn’t been any research in forensic science. But over the years much of it has been done in crime labs themselves. “It hasn’t gotten to the level where they can state findings in a rigorous scientific way,” said Constantine Gatsonis, director of the Center for Statistical Sciences at Brown University and co-chairman of the National Academy of Sciences committee. And rather than being teased out in academic papers and debated at scientific conferences, “a lot of this forensic stuff is being argued in the courtroom,” Mr. Fisher said. “That’s not the place to validate any kind of scientific information.”
Much forensic research has been geared to improving technologies and techniques. These studies can result in the kinds of gee-whiz advances that may show up in the next episode of the “C.S.I.” series — a technique to obtain fingerprints from a grocery bag or other unlikely source, for example, or equipment that enables analyses of the tiniest bits of evidence.
This kind of work is useful, Dr. Kobilinsky said, “but it doesn’t solve the basic problem.”
DNA analysis came out of the biological sciences, and much money and time has been spent developing the field, resulting in a large body of peer-reviewed research. So when a DNA expert testifies in court that there is a certain probability that a sample comes from a suspect, that claim is grounded in science.
As evidence to be analyzed, DNA has certain advantages. “DNA has a particular structure, and can be digitized,” Dr. Gatsonis said. So scientists can agree, for example, on how many loci on a DNA strand to use in their analyses, and computers can do the necessary computations of probability.
“Fingerprints are a lot more complicated,” Dr. Gatsonis said. “There are a lot of different ways you can select features and make comparisons.” A smudged print may have only a few ridge endings or other points for comparison, while a clear print may have many more. And other factors can affect prints, including the material they were found on and the pressure of the fingers in making them.
Sargur N. Srihari, an expert in pattern recognition at the University at Buffalo, part of the New York state university system, is trying to quantify the uncertainty. His group did much of the research that led to postal systems that can recognize handwritten addresses on envelopes, and he works with databases of fingerprints to derive probabilities of random correspondence between two prints.
Most features on a print are usually represented by X and Y coordinates and by an angle that represents the orientation of the particular ridge where the feature is located. A single print can have 40 or more comparable features.
Dr. Srihari uses relatively small databases, including an extreme one that contains fingerprints from dozens of identical twins (so the probability of matches is high), and employs the results to further refine mathematical tools for comparison that would work with larger populations.
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There are certainly many advantages and disadvantages of forensic science. It can be said that fingerprinting, one of the techniques used in forensic science to identify the criminal, is the most useful advance in forensic science. However, we have to be extremely careful when examining fingerprints. This is because there is a possibility that there might be human error, which might even result in the wrong person getting arrested. Similarly, the presence of a person’s fingerprint does not mean that he might have committed the crime, but is at the crime scene before. Hence, to counter this problem, we have to use other evidence to support this. However, fingerprinting also has many advantages. Since no one in the world have the same fingerprint, let alone twins, it is a very important part of forensic science.
From this passage, we can learn more about the advance of DNA Fingerprinting, while is the most exciting development in the current forensic science research. DNA has a particular structure and is easy to be digitalised as compared to fingerprints, as there are a lot of different ways you can select features and make comparisons of fingerprints. DNA, similar to fingerprints, is unique for everyone. DNA samples can be obtained from various parts of the body, as compared to fingerprinting and is thus easier to be identified and analysed. This method is making its way into forensic science, with extensive tests being made and studied carefully by many of scientists, as compared to other investigate tests, which has not been exposed to extensive scientific scrutiny.
In conclusion, DNA fingerprinting is gaining a hallmark in current forensic science research and is currently one of the newest and most reliable sources of forensic science. I foresee that in the future DNA fingerprinting will become the most important aspect in forensic science in identifying criminals. I hope by using this method, it will prevent less people from wrongly accused and the criminals to be arrested as soon as possible.
