In Class Expirements

In order to understand the jobs and environments that forensics analysts encounter, in class we simulated the crime scenes that they may encounter by doing mini labs in groups. 

Fingerprinting 

My Thumb Print

In this lab, we each gathered skin oils onto our thumbs and pressed it down on the table. Fingers always have oil on them and the reason why we gathered more oil was to make the print more visible; the reason we used our thumb was that it would lay down the largest print. After laying down the print, we used cornstarch and brushed it onto the area where we laid the print and the print soon became visible. Following that, we used a light colored tape, lifted the print, and placed it on black paper, which contrasted against the white colored cornstarch. This lab was productive in the fact that it should us an alternative way of gathering and lighting fingerprints from a crime scene if the normal powders are unavailable.    

Hair and Fiber

For this lab, we were required to examine various fibers that a commonly seen today not only at a crime scene but also in everyday life. We first were given sample of African-American hair, Asian hair, cat hair, cotton, dog hair, dyed hair, nylon, silk, synthetic hair, and wool. We then placed the samples under microscope and examined the various properties with each hair and whom they differ from the other hair and fibers. We then created a chart, recorded the characteristics of each sample, and drew a picture of the samples. With this lab, we were able to identify various her samples and their properties that persist with them.


Hairs we tested




Hairs we tested



Lipstick
In this activity, all (including the boys) the students were required to apply lipstick and examine the properties of lips. In order to examine the properties we all acquired and applied lipstick and pressed our lips on individual note cards. Then after pressing our lips on the cars, we examined our lips and recorded different properties that were visible on our lips. Then later we (all the group members) pressed our lips on a sheet of paper and allowed another group to compare those to the ones on the note card and match them together. This lab exemplified the use of looking at the characteristics of things left behind at a crime scene (in this case lips) and observing and recording them in order to find the criminal.

Witness Experiment

For this activity, we tested our ability to remember faces like a witness who witnessed a crime would. We were told to gather faces from magazines and cut out the features such as the nose, eyes, lips, chin, and forehead. Once all the features were out, the face were regenerated and the group member was to remember the face constructed. After 10 seconds, the face were to be jumbled up with other features that had been cut out of magazines and with only the use of their memory, the group member then reconstructed the original face and if it were wrong, they would retry construction. With this lab, we recognized the skill it takes in order to remember and regenerate faces in similar ways that witnesses do in order to provide a description of a criminal.    

Creating a Profile
In this lab, we used all the techniques that we used in the fingerprinting lab, hair and fiber lab, and handwriting lab in order to generate a profile of a possible suspect in a crime. Each group was given 5 similar clues (one set of fingerprints, 2 hair or fiber samples, a torn note, and a red smudge on a piece of paper) and we told to analyze each clue. The first clue was a set of fingerprints and a group member was told to analyze the prints and determine which hand they came from. After analyzing the prints, we concluded the type of prints they were and that they were from a right hand. the second clue was a  hair or fiber that we analyzed and concluded that it was a sample of colored hair. The third was a torn note that we reconstructed and realized that it stated, “You will never find her.” The fourth clue was another hair or fiber sample that we analyzed to be a sample of African-American hair. Finally the fifth sample was a red stain that could have either been made from lipstick, blood, or any other red substance (further testing is needed to determine the stain). We could then build a profile using the clues that were given and analyzed to conclude that:

·         Two people, a African-American and a person with colored treated hair (or one African-American with colored treated hair)

·         The person could be losing blood (assuming blood was the stain)

·         Right hand consists of 2 whorls, 2 tented arches, and an unknown thumb

This lab required us to use problem-solving skills and to analyzed and make educated assumptions about the suspect or victim based off the analyzed clues that were given.





Clue 1

 



                                       

Clue 2



Clue 3

Clue 4

Clue 5

Footprint Analysis

In this activity, we were required to leave a footprint impression in the soil provided and observe the characteristics of the impression. Similar to a actual forensics analysts, we recorded weather information, time, date, location, and direction of the footprint. Then we recorded properties of the print such as the length and width of the shoe impression that was left. All visible characteristics such as the ridges left in the soil were pictured and recorded for analysis. We were soon able to determine the gender and size of the person leaving the print. Males generally leave a deeper print because of their size and a larger print because they usually have larger feet unlike women. With this lab we were able to see and apply the techniques used by analysts in recording and determining the suspect by their foot impression that they could have left at a crime scene.  

Drug Analysis

For this lab, we were given various simulated drug sample that resembled real drugs and were required to properly identify and label them according to the test. First, we were given the “drugs” and were told to dilute them to the point where the substance was mostly dissolved in the mixture. Then we took a small sample of the dilute, tested it with ph paper, and recorded the ph and the color that it displayed. Then we used both LSD and Cocaine reagent that would display a color if the substance were positive for the reagent. For example, the Cocaine reagent would turn blue if the mixture was positive for Cocaine and would remain colorless if it was negative. With the LSD, the mixture would turn yellow if the presences of LSD were apparent. We tested six substances and three were positive of Cocaine while the other three were positive for LSD. This lab provided us with the knowledge needed to understand how to test and verify substances as being positive or negative for drugs.

In the Process of Diluting Substance

Pouring Sample of Diluted Mixture into Test Plate

Poison Lab

For this activity, different stations were set up that held a variety of poisons. At each station, there were three different samples of potential poisons that we (the group) had to identify by using various methods such as pH testing and reagent testing. Ammonia, aspirin, cyanide, iodine, and metal poison are various poisons that we were to identify in the lab. With this lab, we were able to partake in and understand various methods that forensics analysts use in the field. We were also able to use the methods learned in our lab in the crime scene activity done in class.