CSI: Top 10 Questions
Thanks to Matthew Gamette, Forensic Services Quality Manager, and Natasha Wheatley, Latent fingerprint and shoe print/tire track examiner, Idaho State Police for the answers.
1: How do you find fingerprints?
We find fingerprints by using different chemicals or powders to make them appear. Even though the powder method (dusting) is more well-known, we actually develop more prints with chemicals. (From Kate in Mrs. Schultz's class at Dalton Elementary School in Dalton Gardens)
2: When you find evidence, like a fingerprint, how do you know who it belongs to?
Fingerprints are very unique to people. The ridges on the surface of a person's skin develop when they are in the uterus. The pattern of these ridges is what makes each person's fingerprints unique. There are three types of patterns: arches, loops, and whirls. We use these patterns to determine who the fingerprint belongs to. (From Dylan in Mrs. Hudson's class at Dalton Elementary School in Dalton Gardens)
3: If you found a fingerprint on a wall while investigating a crime, how would you know if it belonged to the criminal or the owner of the house?
When we investigate a crime, we also collect elimination prints. These are prints from anyone who could have touched the wall in the house. We get fingerprints from the owner of the house, compare them to the print on the wall, and then eliminate the prints of those who aren't suspects. (From Tallon in Mrs. Hudson's class at Dalton Elementary School in Dalton Gardens)
4: Is it harder to find clues in bad weather like snow?
It can be really hard to find evidence that is buried under the snow. However, sometimes the snow makes it easier because the evidence may be on top of the snow. For example, a suspect walking across the snow may leave a nice set of footprints, or a car driving on a blanket of snow may leave good tire track evidence. (From Kate in Mrs. Hudson's class at Dalton Elementary School in Dalton Gardens)
5: Is it possible to find out if a thief is a boy or a girl?
That is possible. In fact, that is what DNA science is all about. There are specific areas on your DNA that make you male or female. So, when we run a DNA test, we look to see if the suspect is male or female. This is a very important part of an investigation. (From Emma in Mrs. Hudson's class at Dalton Elementary School in Dalton Gardens)
6: How many different types of DNA are there?
DNA is made up of several bases, or chemicals. These bases are organized in a number of different ways so every person's DNA is unique and has a different DNA profile. We look for these differences when we are trying to solve a crime. (From Lauryn in Mrs. Woodall's class at Dalton Elementary School in Dalton Gardens)
7: Do twins have the same fingerprints?
They do not. When the twins are developing before birth, there are different pressures going on. They call this differential growth. Even identical twins do not have the same fingerprints. (From Molly, Carson, Taylor and Alec in Mrs. Peterson's class at Owyhee Elementary)
8: Do you use special cameras in your work?
We do. They are not the typical point and shoot cameras that we usually see. They are very high end, expensive cameras that sometimes come with special filters to let us view blood on very dark clothing. (From Troy in Mrs. Schultz's class at Dalton Elementary School in Dalton Gardens)
9: How many different types of DNA samples can detectives analyze from a crime scene? What are you looking for?
We are looking for anything that comes from a body. DNA is in almost any cell in our bodies. Whether we look at a person's skin, hair or blood, a person's DNA is the same in all of those different types of samples. (From Kaitlin in Mrs. Woodall's class at Dalton Elementary School in Dalton Gardens)
10: What is the hardest evidence to find at a crime scene?
The hardest evidence to find would probably be trace evidence. We're talking about hairs, fibers, and things like that from material. Also, things that you can't see are hard to find, like DNA. (From Porter from Trail Wind Elementary School in Boise)
Click on a Topic:
- Ages Past
- Earth Science
- Human Body
- Science Fundamentals