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AJ275rh

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1-In comparing two hair samples, what aspects of the hair is the criminalist particularly
interested in matching? What other features of hair are important to compare?
When comparing two hair samples, some aspects of the hair the criminalist is particularly
interested in matching is the color, length, and diameter of the hair. Other important features for
comparing hair is the presence/absence of a medulla and the distribution, shape, and color
intensity pigment granules in the cortex.
2 - Why are most hair specimens collected at crime scenes not good sources of DNA?
Most hair specimens collected at a crime scene is not a good source of DNA because
mitochondrial DNA cannot distinguish microscopically similar hairs from different individuals
who are maternally related. You would need a combination of a positive microscopic comparison
and an association through nuclear or mitochondrial DNA analysis for a strong meaningful link
between a questioned hair and standard/reference hair.
3 - List three important considerations when submitting hair samples to a crime
laboratory.
When submitting hair samples to a crime laboratory, some important considerations are having
an adequate number of standard/reference samples, hair from the same area of the body, and the
entire hair is collected.
4 - What is the first and most important step in the examination of fiber? What physical
characteristics of fiber might help an examiner identify it?
The first and most important step in the examination is a microscopic comparison for color and
diameter using a comparison microscope. Other morphological features that could be present to
aid in the comparison are lengthwise striations on the surface of some fibers and the pitting pf
the fiber’s surface with delustering particles added in the manufacturing process to reduce shine.
5 - Name two analytical devices used by forensic scientists to determine the class of a fiber.
The stereomicroscope and the comparison microscope are two devices used by forensic scientists
to determine the class of a fiber.
Reference: Criminalistics, Saferstein, p.260-266)
In a separate email, please give me feedback in two areas:
What is one thing helping you the most in this class?
Being able to work ahead in this class in orde to get the weekly assignments, reading, and
quizzes completed on time has helped me in this class.
What one thing could I change for the rest of the class that would help you the most?
Being able to post our homework assignments without having to email it first and wait for a
response would help the most, so that we would be able to complete everything faster and have
time to respond to our classmates’ posts.
Were the Free books and resources be adequate to complete the course assignments?
The free books and resources provided were adequate to complete the course assignments but I
did prefer to get the answers from the book.
Unit 6 due 11/13
1-Name two physiological factors and two nondrug factors that influence drug dependence.
Two physiological factors that influence drug dependence include the nature of the drug and the
route of administration. Two nondrug factors that influence drug dependence include personal
characteristics of the user and his / her expectations about the drug experience. (p280)
2 - What is the source of most narcotic drugs? From what plant is this substance derived?
Most narcotic drugs are naturally found in the opium poppy plant.
3 - What is the most widely used illicit drug in the United States? Under what class of drugs
is it listed and what are its short-term physical and psychological effects at low to moderate
doses?
The most widely used illicit drug in the United States is marijuana, which is a schedule I
substance. Some short-term physical effects include altered senses, altered sense of time,
changes in mood, impaired body movement, and impaired memory. (Reference: Cannabis Drug
Facts, nida.nih.gov)
4 - On what three criteria does the Controlled Substances Act classify dangerous
substances?
The Controlled Substances Act classifies dangerous substances based on the following criteria:
substance’s medical use, potential for abuse, and safety or dependence liability. (Reference:
DEA.gov)
5 - List and describe the two phases in a criminalist’s scheme of action for identifying a
drug.
There are two phases in a criminalist’s scheme of action for identifying a drug, which includes a
screening test, which is used to reduce the number of possible identities of an unknown
substance, and the confirmation phase, which is a single test that specifically identifies the
substance.
Unit 7 due 11/20
1- List at least three factors that determine the rate at which alcohol is absorbed into
the bloodstream.
In (324)
2 - What is a divided-attention task? Name and describe two divided-attention tasks often
administered during field sobriety tests.
327-329
3 - What is the DRE program? What are its main strengths and weaknesses?
340-342
4 - What three features of paint does a forensic scientist compare using a microscope?
360-361
5 - How can soil evidence be valuable even if the site of the crime has not been ascertained?
?
Unit 8 due 11/20
1 - How are proteins formed? What determines the shape and function of a protein?
400
2 - List three advantages gained from decoding the human genome.
401
3 - What is polymerase chain reaction (PCR) and how is it useful to forensic scientists?
401-402
4 - How should packages containing DNA evidence be stored? Name one common
exception and explain why it should be handled differently and how it should be stored.
402?
5 - List four steps an investigator should take to prevent contamination of DNA evidence.
415
Unit 9 due 11/27
1 - Why is it important that the arson investigator begin examining a fire scene for signs of
arson as soon as the fire has been extinguished?
427-441
2 - List three factors that make investigating arson and explosions particularly difficult for
forensic scientists.
d
3 - Describe the headspace technique for recovering accelerant residues. What instrument
is most often used to detect and characterize recovered flammable residues?
436
4 - What characteristic of an explosive determines whether it is classified as a low explosive
or a high explosive? How is this reflected in the type of pressure wave produced by the
explosive?
?
5 - Name two types of low explosives and list the ingredients of each.
?
6 - List three characteristics of handwriting, as well as three characteristics of writing not
related to handwriting, that an examiner compares when studying a questioned document.
460
Unit 10 due 12/4
Looking back over the class, what are the 5 most important things that you now know.
Being a good investigator is more than using your five senses. This applies in multiple aspects,
from conducting an interview to examining a crime scene.
How crucial it is to gathering forensic evidence is and the different ways they are tested.
The importance of documentation in forensics.
Learning about DNA databases and the different types of DNA at crime scenes.
How physiological factors and nondrug factors influence drug dependence.
Looking back over the class, list the 5 most important things you did to be successful. Five
things I did to be successful in this class was get organized, finish the work ahead of the due
date, takes notes, read the module answers from other classmates, and overall manage my time
well for my class tasks to get done.
Were the free books and resources adequate to complete the course assignments? The free
books and resources provided were adequate to complete the course assignments but I did prefer
to get the answers from the book.
What did you find useful? I found it useful to work ahead in order to meet the deadlines
because it was a lot to have to read, do responses, complete the homework and quizzes. By
getting ahead, I gave myself more time to get other things done.
What changes do you suggest? If there are newer documentaries that we can watch in relation
to the class content, that would be more interesting due to the newer, more updated content.
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