Labs

The following is a list and brief description of various labs I participated in during class that relate to the topic of forensics:

 

Fingerprint Lab

In class, we investigated fingerprints via a fingerprinting lab. In this lab, my classmates and I were required to place fingerprints on both light and dark colored hard, nonabsorbent surfaces. To do this, we were required to rub our thumb in-between our nose and cheek in order to gather natural oils from our skin onto our finger. We then placed our fingers on a dark and light colored surface. To produce the prints, we had to place powders on them. For the dark surface, it was corn starch, for the light surface, it was graphite powder. Then, to lift the prints, we used tape, which we placed on the powder (that had retained the shape of our print, due to the fact that the powder had stuck to the natural oils produced by our skin in the shape of our fingerprint) and then lifted, and since the powder stuck to the tape, we had successfully gathered our fingerprints.

This lab proved to be difficult; it was hard to get the powders to stick to our prints. I believe this is because we were not using the same high-quality items that investigators use to gather fingerprints. However, after multiple attempts, I did gather some fingerprints that I could identify as being under one of the three categories. This lab shows how useful fingerprints can be in an investigation; it can easily identify a suspect due to how unique fingerprints are.

Hair/Fiber Lab

In this lab, my classmates and I were required to observe various properties of hair and fiber samples. To do this, we obtained samples of dog hair, cat hair, synthetic hair, dyed hair, Asian hair, African American hair, nylon, silk, wool, and cotton. We then placed these known samples under a microscope in order to view each of their unique characteristics.

Upon viewing the samples, I noticed that human hair and synthetic hair was usually uniform in color, while fibers had a variety of colors and shapes. For example, African American hair had a dark brown outline with a lighter colored center, while wool had a dark blue or purple outline with a clearer blue center. This lab helped us to be able to identify various samples of hair or fiber samples upon observing their characteristics under a microscope. This lab proves that hair and fiber can be a valuable asset in an investigation because it can profile a suspect or even show where the suspect has been if fiber samples match.

Lipstick Lab

In this lab, I was required to identify various properties of lips. In order to do this, my classmates and I applied lipstick and then pressed our lips to a notecard in order to leave a lip print. We could then effectively observe various characteristics of our lips. For example, we could see if a person had chapped lips, a certain curve or space in their lips, or the size of the lips. We then applied a second print to a sheet of paper that we left at our tables. We switched tables, and then were required to see if we could match one person’s lip print to their print on the table. My group was fairly successful; we identified the clear prints easily based on their size, shape, or any other unique characteristic, but other prints were indistinguishable, which we could not identify. This lab can be used in an investigation if the suspect left a kiss on a victim while wearing a lot of lipstick.

Creating a Profile Lab

In this activity that my group and I participated in during class, we were supplied with five individual clues that consisted of a handwriting sample, two hair or fiber samples, a lip or blood sample, and a set of fingerprints. My group and I were required to see if we could identify the type of person who could’ve committed a crime and left these clues at the scene. We determined that the suspect was a female African American, and that there was also a dog at the scene, based on our hair, fingerprint, and handwriting samples.

This lab made us use a majority of our forensic knowledge. We applied our knowledge of handwriting, fingerprints, hair, fiber, and lipstick in order to create a plausible profile for the suspect of our given crime. This lab is extremely useful for investigations because it is what is used to identify your suspect, or at least to narrow down the possibilities.

Witness Lab

In this activity, my group and I tested how good of a witness we would be in an investigation. To do this, we found various pictures of people in a magazine, cut out the pictures, and then separated them into various groups by facial features. For example, we cut out the faces eyes, nose, hair, mouth, etc. We then chose a group member, gave them ten seconds to memorize the face, then separated it and observed if they were able to reconstruct the face.

This lab tested my group’s memory. We were very successful; all four of us reconstructed the faces. However, I think this activity would’ve been far more challenging and realistic if it had been with actual people who changed their appearance and then required us to identify them. This resembles an investigation because it tests if the witness to the crime has a reliable account of the suspects appearance or not.

Foot printing

In this lab, my group and I had to leave footprints in a soil sample and then observe the various properties of the print. We measured the print, recorded the weather information, and observed the design on the print. It was fairly easy to identify the size and gender of the person based on the size of their print, however, identifying race or age is not practical with this type of test. This lab would be useful for an investigation if a footprint was found at the scene, because you could effectively identify the gender and relative height/weight of the suspect.

    

Photo courtesy of Audrey Brown

Drug Analysis

For this lab, my group and I were provided with various fake drug samples were required to identify them. To do this, we had to mix the sample in water, and then test the sample with pH paper, a cocaine identifier that would turn the sample blue, and a LSD identifier that would turn the sample yellow. We found that four out of the six samples tested positive for cocaine, while two were positive for LSD. This lab is a practical use in an investigation because you can identify if the suspect or victim are users of an illegal substance, thus adding to the profile of the suspect.

Poison Lab

                                                         Photo courtesy of Ashley Eakins

In this lab, varoius stations were set up that contained different poisons. Some poisons that were provided were cyanide, sugar, metals, iodine, etc. My group and I were required to use various indicators to determine which samples were poisons, and if so, what kind of poison. We successfully identified each poison based on their pH, color after an indicator was applied, and other characteristics such as smell.

Identification of poisons can be of great use in an investigation. There are always tell-tell signs to determine whether or not a person was killed by being poisoned, in which case it is crucial to identify what poison was used. By being able to identify what a victim was poisoned with, you are able to build the profile of your suspect and take one step closer to solving the crime.