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Forensic Science

Directions: Please read the following passage and answer all of the accompanying questions.


1 The term forensics simply means analytical and is commonly used to describe the science used at crime scenes. Today forensic science has really taken off. Specialized forensics programs are being developed at universities, and TV productions, like Crime Scene Investigations, CSI, are popularizing the modern technology used in investigating crime scenes.
2 There are many techniques that help scientists solve a crime. Photo enhancement, DNA electrophoresis, toxicology, entomology, and anthropology are all common tools. One of these techniques, photo enhancement, is quite useful. When police take or obtain photos of the scene, it is often difficult to distinguish certain features of objects. With computers, investigators can magnify, brighten, darken, or adjust the color settings of images to make them clearer. Specialist in labs use software similar to what many people use at home with their digital cameras. Notice in the first picture many of the objects are indistinct. With photo enhancement, the cars, train, people, and signs are easier to see. The third picture is a magnification of a sign that would otherwise be unreadable.


image courtesy of TransTech Group, Inc.
3 DNA technology is one of the most useful tools a researcher has available. It is incredibly accurate. With the exception of identical twins, everyone has unique DNA. It is also relatively easy to obtain since DNA samples can be taken from hair, skin, blood, saliva or semen. Since 1992 when the National Research Council approved DNA testing as a reliable means to identify criminals, it has been used in court cases all over the country.

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The process of examining DNA evidence is complicated. Scientists use special enzymes to cut up DNA at certain points in the genetic code. The enzymes look for a specific series of molecules and then perform an incision. After the DNA has been sliced up, it is placed in a special gel and run through an electric field. The longer, heavier fragments take longer to migrate through the gel, and eventually, the pieces of DNA will separate by mass. Scientists may then mark DNA strands with special dyes making it easier to see and photograph the DNA fingerprints. DNA fingerprints differ from regular fingerprints in that, even though they are unique to the individual, relatives can be identified by similarities. The picture below contains a sample DNA fingerprint.


image courtesy of The Why Files



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image courtesy of Nu Magazine
Toxicology is another important tool of lab research. It is used to identify what poisons have entered a victim’s body. Toxicologists utilize a battery of chemical tests to probe the body for traces of poisonous substances. This is especially important because of the threat of biochemical attacks from terrorists at home and abroad. In one case several members of a church in New Sweden, Maine all became violently ill. One person died and 12 others were hospitalized. Many were dumbfounded by the illnesses, but forensic science stepped in to help solve the mystery. Chemical tests revealed their coffee had been spiked with arsenic, which allowed them to eventually find the culprit.
6 Entomology, the study of bugs, is surprisingly useful at crime scenes. Identifying the type and quantity of bugs on a body can help the investigators set up a post mortem interval, or a period of time in which the death could have taken place. If a certain bug’s larvae are found on the body and the detective knows how long the eggs take to develop or hatch, then he can deduce a time frame for the murder.
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Looking at a victim’s bones can give an anthropologist even more information about the person’s life and habits. Using the same techniques involved in archeology, an anthropologist can identify gender, race, age, health, pregnancies and even cancers in a victim. Craniosacral measurements (skull measurements) have been standardized for all ages and races so an anthropologist examining a skull can easily identify the category into which a victim would fit. Chips or ridges in the bones can also indicate where a person’s muscles have been used extensively. This can give the scientist a clue to the person’s profession. A dancer, for example, might have unusual wear on her feet, where as a secretary might have defining markings on her hands and wrists.


Forensic science gives us the opportunity for a safer future. Murderers and other criminals can be more swiftly and accurately identified and innocent more easily protected. But even more than that, it makes each of us more aware of how we effect the world around us. Our bones, our blood, and our bodies all leave clues about our existence and the impact of our lives for those who are willing to look for the clues. In a sense, forensics gives us the hope that the significance of our lives and the reason for our deaths will be understood and remembered.

image courtesy of The Advocacy Project

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