Forensic Biology – DNA
Scenario: It was a beautiful sunny morning in one of America’s most beautiful cities. There were early morning joggers making their way through parks that were lined with palm trees from one end of the park to the other. The atmosphere throughout the city was so electric and it seemed as if that day was going to be one of the best days ever. Who knew at that very moment, there was an individual stalking women at random so he could rape and kill them.
At about 12:00 noon, a boyfriend of a woman, who was a nude dancer at a gentlemen’s club, came home to find that she had been brutally stabbed 65 times and posed in a crucifix position in the room of their roommate that shared a two bedroom apartment with them. About one month later, a college coed was doing her laundry as she prepared to study for her LSAT exam for Law School. At about 2:00pm, her roommate came home to find her stabbed to death and it appeared that she had been sexually assaulted. Her body was posed in the same crucifix position. About 3 months later, a high school senior and her girlfriend were visiting her brother and decided to go to the pool one morning in the apartment complex for a swim and to do a little tanning. The high school senior decided that she had gotten enough sun so she returned to her brother’s apartment alone. She told her girlfriend that she would leave the door open for her so if she was in the shower, she would be able to enter the apartment. When the high school senior returned to her brother’s apartment, she was followed by an unknown man. About 30 minutes later, the girlfriend returned to the apartment to find the high school senior stabbed to death with a sock tied around her throat. She had also been posed in the crucifix position.
What did each one of these women have in common? They were all brunettes, they were all young and beautiful, and the all lived in the same apartment complex. When the physical evidence was collected from each crime scene, there were several items that contained human blood and a few items that contained human seminal fluid. Could the same person be responsible for all three of these crimes? Could the blood and seminal fluid be scientifically analyzed to reveal their origin and help recreate the crime scenes and help solve these cases? Were these cases the work of a serial killer or were they committed by different individuals?
This audio will explain the evolution of Deoxyribonucleic Acid (DNA) as a primary tool in determining the origin of blood, semen, saliva, hair roots, body tissue, and bones. You will learn about the history of the previous method of ABO Blood Group Typing and how it was used to identify body fluids left at a crime scene and why DNA techniques have replaced them. Through the use of a power point presentation, you will learn the screening and confirmatory tests that are used first to identify if the stains are human body fluids before any individualization techniques are employed to determine their origin. This audio will also discuss two criminal cases that will illustrate why no two people can have the same DNA genetic code unless they are identical twins. Finally, you will learn what DNA is, how it is configured, and what specific scientific techniques can be used to break the double helix of the DNA chain to reveal its individual genetic code.
So go ahead and click on the appropriate box and find out how a nucleus can be broken down and its chromosomes can be analyzed to obtain scientific results that can help you find out what really happened in the three criminal cases that started all of this commotion in the first place!