Friday, July 13, 2012

Forensic Science Quest 2

Our second week of Forensic Science Camp has been an exciting one! We explored many crime scene investigation methods, ranging from DNA and blood analysis to mammal tracks! There was even a mock crime scene on Friday that the campers helped solve!

What happens when you add water to cornstarch?

We began our week with physical and chemical properties. We did chromatography (pen ink) tests, studying how 6 different pen inks spread when they came into contact with water. We then conducted a test on a ransom note, and compared it to our 6 samples (taken from the different suspects) to determine who the criminal was. We also explored mystery powders. We studied 4 different powders, noting their appearance, texture, smell, and their reactions to water, iodine and vinegar. We then were given a mystery powder, and had to use our previous tests to determine which of the 4 powders it was!
Checking out the results from the chromatography tests
Extracting DNA from Bananas

On Tuesday, we extracted DNA from bananas in a special demonstration. We learned about how DNA can be used as evidence in solving crimes, and how DNA, like fingerprints, is always unique to each individual. 

The counselors using the Hemastix.

We also did two experiments with blood. First, we identified which of 4 substances was real blood by putting samples in a Hemastix. The Hemastix has tubes of chemicals inside of it that, when they react with real blood, turn the color blue.

The Hemastix turns blue when it reacts with blood.

Testing the simulated blood on different surfaces.
We also experimented with simulated blood spatter to help us understand how blood can look on different surfaces and when dropped from various distances. On porous surfaces, like a sponge, a blood drop with have a jagged edge, while blood on non-porous surfaces, like a table, with have a smoother, rounder edge. We also discovered that blood drops are larger when dropped from a greater distance. We used this information to help us figure out how far away a victim was standing away from a wall when he was shot.
Looking at blood spatter

Dusting objects for fingerprints
On Wednesday, we lifted fingerprints and then examined them to find patterns. Fingerprints are an example of latent prints, which are hidden impressions left by skin ridges on a surface. We touched bottles, light bulbs and jars to leave our fingerprints, and then lifted them by brushing magnetic powder on the area and pulling them up with tape. We then examined them for patterns and points of identification. 

Dusting objects for fingerprints

Comparing handwriting samples with a ransom note

We also did a handwriting analysis, in which we had to match the handwriting of a ransom note with samples from several suspects. We did this by studying the tilt, shape, style and connectedness of their letters.

Officer Cargill showing us the metal detector that police use.

On Thursday, we had a visit from a U of M Police Officer, who talked to us about Forensics Careers and some cool Forensic Scientist tools! 

Officer Cargill lifting a fingerprint.

We also talked about Wildlife Forensics. We looked at mammal and human tracks to figure out the events in a scene. We learned that we can use our forensics skills in wildlife habitats, forests and parks to track endangered animals, convict an animal poacher or find an animal that might be a danger to people.

Officer Cargill showing us the alternate light source used to find fluids.

Kyle's groups working on sketching the crime scene.
On Friday, we conducted a mock crime scene, in which a very valuable fossil was stolen from the museum and a murder took place. We collected evidence at the crime scene, and used our forensic skills to analyze fingerprints, handwriting, blood spatter and tools to find the criminal.

Where the body was found.

Placing evidence markers and collecting evidence.
Swabbing the blood to test it later.

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