1. What are the three types of fingerprints found in the human population? How often does each occur? Loop, Whorl and Arch. Loop occurs in 60-65 percent of the population, Whorl occurs in 30-35 percent, and Arch only about 5 percent. 2. What is a medulla? What do forensic scientists use this for? A set of cells that runs through a hair. Forensic Scientists use this to distinguish animal hair from human hair. 3. What is a precipitin test? What is it used for?
A precipitin test is a test to distinguish between animal and human blood. It is used to tell whether the blood found is from a human or animal. 4. What makes fingerprints individual? How do scientists match a fingerprint to a specific person? The individuality of fingerprints is due to ridge characteristics. They look for point-by-point comparisons in order to determine whether two fingerprints are the same. 5. How are fingerprints discovered at crime scenes?
Devices like the RUVIS help to find fingerprints along with fingerprint powders.
Critical Review Questions
1. Of the three types of physical evidence discussed in this module, which one do you think you would be most interested in working with in an investigation? Why? I think I would be most interested in working with blood. Working with blood would be interesting because you can gather a lot of information from the smallest of blood samples. Such as where the person was when the blood splattered from them and if it’s human or animal blood. 2. What do you think would be the most challenging aspect of collecting and analyzing hair samples? Why? I think the most challenging aspect of collecting and analyzing hair samples would be matching it to a particular person. I think this would be difficult because hair samples can vary in age and location. Plus studying hair is key because it can eliminate possible suspects based on its properties.
Such as texture, length, color, and chemicals. 3. Why do you think forensic scientists study bloodstain patterns? What can be learned from them? Forensic scientists study bloodstain patterns to determine what took place at the crime scene. Things that can be learned is the direction the blood was traveling in, angle at which the blood hit the surface, and it can help determine the spot where the blood came from. 4. Out of the types of evidence discussed in this module, which one do you think is the most important piece of evidence? Why? I think the most important piece of evidence is blood. Blood is the most important because it’s actual DNA that can link the exact person to a crime scene.
Unlike hair blood is more reliable because it rules out other possible choices. 5. Why was the bite mark evidence so important in the Bundy case? If the case happened today, do you think investigators would have more information to work with? The bite mark evidence was so important because it was the only substantial piece of evidence that could prove Bundy committed the crimes. Investigators might have more information to work with maybe they would find fingerprints and hairs at the crime scenes with the proper equipment.