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Last updated on October 13, 2007
Introduction
Of all the technologies developed over the past few decades for forensic investigators, DNA identification has become the most widely used and respected mode of evidence to tie a person to a crime scene. A criminal can now be tied to a crime scene with a small piece of hair, a miniscule drop of blood, saliva or a single fiber of just about any material worn at the time of the crime. DNA is different for every person except identical twins but remains constant from cell to cell of any individual. This method of evidence has put many criminals behind bars but has also allowed many wrongly convicted people to be set free.
Assignment One
Read how four men were convicted only to have DNA evidence later prove them innocent. These Four Cases are examples of how technology can change how we view evidence and the right to a fair trial. Explain how you think society should compensate someone wrongly accused after they have served several years in prison for an offense that they did not commit.
Aside from crime scene uses, DNA identification can also be used to positively identify the remains of people long since deceased. In this next example you can read about the use of DNA testing to put a Vietnam era soldier, Michael Blassie, to rest after several decades.
Assignment Two
So what exactly is DNA? Let's look at what is involved in the lab in extracting a DNA Fingerprintfrom a piece of evidence. Here's a fictitious Crime Scene in which you will enter the lab and try to determine who commited the lollipop crime. So let's create a DNA Fingerprint and find the Culprit!
As you can see there are many steps involved in processing DNA. As with any scientific procedure you can destroy the entire body of work with just one small error. In the case of DNA this could mean that a criminal is set free.
Using the DNA Technology Timeline answer the following questions:
In what year was DNA first isolated from cells?
What does the word "gene" mean in Greek?
Who developed DNA sequencing techniques and subsequently won the 1980 Nobel Prize in Chemistry?
Can you think of any other times where DNA can be used to help reach a positive conclusion?
Read this article on the use of discarded DNA and writs a brief essay describing whether you believe a person's consent should be obtained prior to taking a DNA sample. What side of this issue do the courts support?