Crime Scene Investigation

In this activity, I was grouped with other classmates and required to investigate a crime scene. When we entered the scene, a night club, the first thing we did was take multiple pictures of the various exhibits, just as you would at an actual crime scene. When then went on to examine the various exhibits. This is what we found:


Exhibit 1: A red headed woman was lying on the hood of a car, apparently killed by having her throat slit, or possible strangulation.



Exhibit 2: A sample of blood was found that was O negative. This blood matched the type of both the victim, Ginger Snap, and the suspect, Candi Stores.

Exhibit 3: A tented arch fingerprint was lifted that matched the suspect Candi Stores.

Exhibit 4: A mixed drink was found with lip prints on the rim from a dark red lipstick. Our team analyzed that the person who drank from the cup left a large, heavy print with their bottom lip. This also led us to believe that the person was female.

Exhibit 5: My team and I then went on to analyze the drink itself to see if it contained any poisons or illegal substances. All tests turned up negative.

Exhibit 6: A fiber sample was found at the scene. Upon analysis, it was discovered that the fiber was cotton. This was concluded by viewing the fiber through a microscope and comparing it to known samples from our previous lab in class. The discovery of this fiber led us to believe that a struggle occured between the two people.

Exhibit 7: A handwriting sample was found that read "Please help me!" Upon analysis, it was concluded that the handwriting was that of the victim Ginger Snap. This conclusion was reached because once the sample was compared to a known sample of Ginger's handwriting, we distinguished that both samples had narrow loops, small letters that were close together, and the words slanted right.



Exhibit 7A: A second handwriting sample was discovered that read "I needed the money." Upon analysis, it was concluded that the hadwriting belonged to the main suspect Candi Stores. This conclusion was reached because when this sample was compared to a known sample of the suspect's handwriting, it was distinguished that both samples had distinct 'a's, letter size varied similarly in both, the words did not line up, and the letter 'e' matched in both.

Exhibit 8: A black fiber sample was discovered at the scene. Upon analysis, it was concluded that the fiber was wool. This was concluded the same way that the cotton sample was. This further confirmed that a struggle occurred at the scene.

Exhibit 9: A gold necklace was discovered at the scene. Our group decided that this item was of no importance to the investigation, probably belonging to a bystander.

Exhibit 10: A double loop fingerprint was discovered that matched the victim Ginger Snap.

Exhibit 11: An ulnar loop fingerprint was discovered on a glass surface that we proceeded to lift. Upon analysis, it was concluded that the fingerprint was of no importance to the investigation, probably belonging to a bystander.


Conclusion: Fingerprints discovered at the scene match the main suspect Candi Stores and the victim Ginger Snap. One of the women was under the influence of alcohol. Handwriting analysis suggests that Ginger Snap was suspicious of what was to come, while Candi Store was paid to the victim. Blood samples discovered at the scene match the victim. Loose fibers suggest a struggle occurred. It was concluded that Candi Store murdered Ginger Snap by way of cutting the victim's throat. This was done in order to recieve an unknown amount of payment from an unknown source, most likely the unidentified bystander, who left a fingerprint and necklace at the scene. It is also possible that the necklace was used to strangle the victim, however, no DNA was discovered on the piece of jewlery.

(All photos in this section are courtesy of Ashley Eakins, who was one of my group members for this activity)

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.

Handwriting Analysis

Handwriting is very useful for criminal cases. It can be used to identify forged checks, signatures, or even to identify someone from a note that was written by them. People have been interested in the relationship of the writer to their handwriting since as early as the 17^TH century. Handwriting analysis, however, did not truly emerge until the late 19^TH century, when a French abbe founded a school that tried to compare writing to traits to the writer. It was not until 1915 when a teacher from Kansas made a true breakthrough. The teacher noted that it was not the letter that defined the writer, but instead it was the shapes that formed the letter that made a writer’s handwriting unique.

http://www.torontohandwritinganalyst.com/history.html

There are 12 characteristics of handwriting. The list below is found at http://www.clt.uwa.edu.au/__data/page/112506/fsp10_handwriting.pdf

Line quality: Are the pen marks smooth and free flowing or shaky and wavering? This can be connected to the speed that the document was written at.

Spacing of words and letters: What is it the spacing between letters and words? Is it consistent?

Ratio of the relative height, width and size of letters: What is the ratio? Is it consistent?

Pen lifts and separations: Does the person stop to form new letters and begin words? Forgeries may have lifts in unusual places.

Connecting strokes: Are capitals connected to lowercase letters and are there connecting strokes between letters and words?

Beginning and ending strokes: Are these straight, curled, long or short, an upstroke or a down-stroke?

Unusual letter formation: Are there any unusually formed letters such as backward, letters with a tail, or unusual capitals?

Shading or pen pressure: Is the pen pressure on the upward or the downward strokes?

Slant: Is slant left or right or straight up and down? Is there consistency between the slant of letters.

Baseline habits: Is the writing above or below a line?

Flourishes and embellishments: Are there any? If so what are they?

Diacritic placement: How are the t’s crossed? Take note of the dotting of i’s, j’s. For example, are the dots to the right or left of the letter?

In a lab I participated in during class, I was part of a group in which we wrote a sentence both in cursive and regular print that contained every letter of the alphabet. We then had to switch papers, and try to freehand forge another person’s handwriting and then trace their handwriting. Freehand forging was very difficult; it is nearly impossible to replicate exactly another person’s writing. You have to copy the size of the loops in their letters, the placement/slant of the words, the dotting/crossing of certain letters, the pressure of the writing utensil, etc. Tracing was easier, but still very difficult. It is very hard to imitate how much pressure the person applies to their writing, how thick the lines of their letters are, and the slant/curve of their lettering. However, I did find tracing to be a lot more effective in producing a similar copy to the original handwriting.

After completing the previously mentioned activity, we were then required to write a ‘check’ in our own handwriting and then trade it with another person. We then had to attempt to identify who wrote the forged checks. It was fairly easy to identify who wrote the checks. Each check had very distinguishable features, such as the size of loops, slant of words, curves of letters, etc. We were successful in identifying the original writers, based on the fact that handwriting always provides the tell-tell signs of forgery, and if you are provided with an original sample, you can very nearly identify who wrote the forgery based on their handwriting characteristics.

One famous case in which handwriting analysis was used involved a German publisher who claimed that he had obtained a compilation of sixty-two notebooks that comprised Adolf Hitler’s diary. When compared to known samples of Hitler’s handwriting, analysts concluded that the documents were genuine. However, upon further investigation of the ink and paper used in the documents, the investigation revealed that the dictator could not have written the documents. This shows that it is possible to imitate handwriting and be successful.

http://www.enotes.com/handwriting-analysis-reference/handwriting-analysis

Hair and Fiber Analysis

In 1857, the first scientific report regarding the scientific study of hair came out, which introduced the world to the concept of using hair in criminal investigations. The concept grew extremely quickly after the microscopic examination of hair came about in the early 1900’s. Since then, a series of literary works came out about the analysis of hair, which established hair analysis as a viable mean of use in criminal cases for investigators.

Fibers are also usable in criminal investigations. They can be used to place a suspect at a certain area that is found to have similar fibers. Some major types of fibers include polyester, cotton, nylon, silk, and wool. Each fiber has distinguishing features when viewed under a microscope. However, due to increased quality of these materials by manufacturers, sometimes certain fibers are difficult to differentiate from one another.

Fibers can place a suspect at a certain place. This is because fibers from one place can be transferred to a suspects clothing, and from there to the suspect’s car or other belongings that fibers can attach to. Hair samples would prove that the suspect was with a certain person, and depending on the condition of the root of the hair, it can be determined if there was any form of struggle; if the root is torn or has a hint of blood, then it would be revealed that a struggle took place. If the hair or fiber is visible, it can be gathered by simply picking it up with your fingers. Fibers or hairs that are smaller can be gathered by using tape to stick to the item and remove them.

Hairs and fibers are analyzed by viewing them through microscopes. Hairs have distinct features in regards to determining the suspect’s ethnicity. For example, Asian hair is very dark when compared to African hair, which is brown. By observing a hair sample through a microscope, an investigator should be able to determine the race of the person. Fibers can be identified by comparing them to other known samples. For example, if there was a question as to what type of fiber a sample is, it could be compared to other known samples in order to be identified.

Hair and fiber data is relatively useful in the solving of crimes. As previously mentioned, the samples can place a suspect at a certain are or with another person, can determine if a struggle occurred, and can determine the race of a person. However, it cannot be used place a date of occurrence or a face on a particular crime/suspect.

Hair samples were used in a case involving the murder of a US drug agent in 1985. Investigators found that hair in the house of the agent matched the hair of the defendant accused of the agent’s murder. However, as previously mentioned, this does not solidly prove that the defendant committed the murder, but does place him in the house of the agent, which the defendant had originally denied.

 

http://articles.latimes.com/1990-06-20/local/me-174_1_hair-fibers
http://www.centralreg.k12.nj.us/webpages/SHopson/files/hair.pdf
http://www.hshairclinic.co.uk/_images/hair_structure.jpg
http://www.crime-scene-investigator.net/collect.html#4
http://www.ehow.com/about_6102496_forensic-science_-hair-fiber-analysis.html

Fingerprint Analysis

A fingerprint is the pattern of skin on the tip of each of your fingers. They form when pressure is applied to a child’s developing fingers before they are born. Fingerprints are extremely unique; there’s a one in sixty-four billion chance that your fingerprints match someone else’s. The chances of finding two like pairs of fingerprints are smaller than finding two like pairs of human DNA. Fingerprints date a few centuries back; they were used to signify trade and used for identification, but weren’t used for criminal means until the middle of the nineteenth century. During the late nineteenth century, in 1892, is the first record of fingerprints being used in a criminal investigation. This is when an Argentinian police officer utilized fingerprints in order to identify the murderer of two boys. When confronted with the evidence, the perpetrator confessed, marking the beginning of using fingerprints as evidence. In 1896, Sir Edward Henry established the Henry Classification System, by which fingerprints could be classified by their shape and distinguished among one another. Henry’s system soon became the primary system of use for the world. In 1901, the first ever Fingerprinting Bureau was established by Scotland Yard, soon followed by New York state prisons in 1903, and later, the FBI.

http://science.howstuffworks.com/fingerprinting3.htm


The act of lifting fingerprints plays a vital role in determining the possible suspects of a crime. There are three kinds of fingerprints: direct, latent, and plastic. Direct prints are fingerprints that are made after a person touches a surface after having come into contact with an easily visible substance, such as ink, paint, or blood. Latent prints are formed when fingerprints are made through the transfer of bodily fluids like sweat or oils. Lastly, plastic prints are developed when one’s fingers come into contact with a soft and/or porous surface. Direct prints are easily observed due to the ability to spot them visually. Conversely, latent or plastic prints are very difficult to find due to their being invisible to the unassisted eye.


When developing fingerprints on hard and nonabsorbent surfaces, like walls, glass, or tile/hardwood floors, the application of a powder to the prints is normally the most effective way of collecting them. When developing fingerprints on soft and/or porous surfaces, like cloth or paper, the application of a chemical is the most effective way to develop the prints. The color powder used to develop prints on hard surfaces depends on the color of the surface that the print is on. Dark powders such as carbon or charcoal powder are most effective on light colored surfaces, while a gray powder from aluminum is typically used for dark colored or mirror-like surfaces. Powders are applied using a brush, and stick to sweat and/or body oils in the fingerprint to make it easily visualized. The prints are then normally lifted with tape, because the powder will stick to the tape while maintaining the shape of the print.

Chemicals such as silver nitrate can be used to develop latent prints. After silver nitrate is applied, the fingerprint is developed by exposure to ultraviolet light. This occurs because of the reaction between the salt in one’s sweat and the silver nitrate, which form silver chloride, which is invisible. After a 3% solution is applied to the object containing the fingerprint and then exposed to ultraviolet light, a print will be shown in a rusty or black color. Then, investigators will most likely photograph the print for comparison to others.

http://www.bxscience.edu/publications/forensics/articles/fingerprinting/f-fing03.htm

There are three basic shapes of fingerprints. They include: arches, whorls, or loops. Arches look like a bump in the lines on your fingerprint. They can be gradual or steep. Whorls appear to be circles on your finger. They can be simple circles, or have a more sophisticated pattern. Loops look like waves in your fingerprint. Like whorls, they can be simple, or more intricate in nature.