Forensic Science Benchmark 1 Study Guide
1. Know definitions of forensic science, criminology and criminalistics.
2. Know ways that forensic science is depicted inaccurately and accurately on television.
3. Know what criminal cases and civil cases are.
4. Know how evidence at a crime scene should be documented.
5. Know physical and emotional stresses that forensic scientists have to handle.
6. Know questions other than questions about a person’s death that forensic scientists try
to answer.
7. Know the difference between a lay witness’ testimony and an expert witness’
testimony.
8. Know who can be an expert witness.
9. Know who determines if a person can testify as an expert witness.
10. Know what is used to determine if a person is qualified to testify as an expert witness.
11. Know what phrases that forensic experts use when they testify since there are no
absolutes in forensic science.
Crime Scene Investigation
1. Describe the first priority and second priority of securing the crime scene.
2. Distinguish between direct evidence and circumstantial evidence. Give examples of
each.
3. Distinguish between class and individual evidence. Give examples of each.
4. Describe the role of the following personnel at a crime scene: police officers, district
attorney, crime scene investigators, medical examiners, detectives, specialists
5. Distinguish between primary and secondary crime scene. Give specific examples of each.
6. Where is a rough sketch of the crime scene made?
7. What elements should be included in a rough sketch?
8. What is the most important element of taking photos at a crime scene?
9. What is Locard’s Exchange Principle?
10. Describe the proper method for opening a sealed evidence bag and then resealing it.
11. Why is it so important to properly document the chain of custody for evidence?
12. Know the correct order of the seven S’s of crime scene investigation and be able to give a
general description of each “S”.
Fingerprints
1. Who created the first system of classification and identification? Alphonse Bertillon
2. Who developed the fingerprint classification system that is used in the United States?
Galton and Locard
3. What type of characteristic is a fingerprint? (individual or class?)
4. What is the purpose of skin ridges? To be able to grip things
5. What is another name for a dermal ridge?
6. Where on the human body are these ridges located? Basal layer
7. When a person touches something, he/she leaves behind a fingerprint. What does this
impression consist of? Oil, water, and salts
8. Anatomy of a Fingerprint:
a. What is the outer layer of the skin called? epidermis
b. What is the inner layer of the skin called? dermis
c. Which part of the skin actually causes the ridge patterns of a fingerprint?
d. Which structure in the skin produces the materials that leave fingerprints?
e. Where does the oil that is deposited with fingerprints come from? Sweat glands or
touching hair and skin
9. When are a person’s fingerprints formed? 10th week during pregnancy
10. Can fingerprints be permanently destroyed? no
11. What are the three main patterns of prints, and how common (%) is each
12. Be able to identify:
a. Radial loop
e. Double loop whorl
b. Ulnar loop
f. Accidental whorl
c. Plain whorl
g. Plain arch
d. Central pocket whorl
h. Tented arch
13. What is a core? The center of a fingerprint
14. What is a delta? The triangular shape in whorls and loops that extends from the
core
15. Define ridge count. Measuring the ridge from the core to the delta
16. Do identical twins have the same fingerprints? no
17. What is the term for the small details that result in unique ridge patterns? minutiae
18. How many individual ridge characteristics are contained on the average
fingerprint? 150
19. How many matching characteristics are needed for a case in court? 8-16
20. Be able to identify these minutiae:
a. Bifurcation
a. Independent ridge
b. Ridge ending
b. Spur
c. Lake or enclosure
c. Bridge or crossover
d. Dot or island
Key Individuals to know:
1. Sir Arthur Conan Doyle
8. Hans Gross
2. Mathieu Orfila
9. Edmond Locard
3. Alfonso Bertillon
10. J. Edgar Hoover
4. Leon Lattes
11. Paul Kirk
5. Karl Landsteiner
12. Dr. William Bass
6. Calvin Goddard
13. R.F. Borkenstein
7. Albert Osborn
14. Alexandre Lacassagne
Individual vs Class Evidence:
**KNOW THE DIFFERENCE BETWEEN THE TWO and BE ABLE TO
RECOGNIZE EXAMPLES!!!
1. List the A-B-O antigens and antibodies found in the blood for each of the four
2. Define chromosome and gene.
1. Describe how a double strand DNA replicates itself. What are the implications
of this process for forensic science?
2. Understand how DNA can be cut and spliced into a foreign DNA strand.
3. List the necessary procedures to be taken for the proper preservation of
bloodstain evidence for laboratory DNA
4. Describe techniques for rifling a barrel.
5. List the class and individual characteristics of bullets and cartridge cases.
6. Explain the utilization of the comparison microscope for the comparison of
bullets and cartridge cases.
7. Distinguish caliber from gauge.
8. Explain the IBIS system.
9. Explain the procedure for determining the distance from a target a weapon was
fired.
10. Describe the laboratory tests utilized for determining whether an individual has
fired a weapon. Emphasize the limitations of the present techniques.
11. Explain why it may be possible to restore an obliterated serial number.
12. List the procedures for the proper collection and preservation of firearm
evidence.
13. Explain how a suspect tool is compared to a tool mark.
14. Explain the forensic significance of class and individual characteristics to the
comparison of impressions.
15. List some common field reagents used to enhance bloody footprints.
1. A nucleotide is made of three parts: a ___________________ group, a sugar called __________________,
and a nitrogen _____________________
2. In a single strand of DNA, the phosphate group binds to the __________________ of the next group.
3. Base pairing rule states that the DNA of any species contains equal amounts of __________________ &
____________ and also equal amounts of __________________ & ____________________
4. Wilkins and Franklin studied the structure of DNA using _________________________.
5. In DNA, thymine is complementary to ________________ ; cytosine is complementary to _____________
What enzyme unwinds are unzips the parent strand? ___________________
10. What enzyme glues the new DNA strand together? __________________________________________
11. The two sides of the DNA helix are held together by __________________________________________
12. Write out the complete name for DNA: __________________________________________
13. What is the matching strand of DNA to: ATA
CCG GAT GCT GCA GCT
14. On the diagram:
Circle a nucleotide.
Label the sugar and phosphate.
Label the bases that are not
already labeled
RNA and Protein Synthesis
DNA  RNA PROTEIN
The Structure of RNA
RNA is another type of nucleic acid. Like DNA, it is made of a long chain of nucleotides.
However, there are 3 main differences between RNA and DNA. Fill in the differences between
RNA and DNA.
RNA
DNA
Types of RNA
There are 3 main types of RNA that help with making protein. Fill in the missing type of RNA and
functions.
Type of RNA
Function
Transcription
DNA
RNA
Transcription is the process of making an RNA strand that complements one side of the original DNA
strand. This happens inside the ______________ of a cell, where DNA is located. Fill in the
blanks to the steps of transcription:
The enzyme _________________________ is needed for the process of transcription. This
enzyme:
a) binds to regions of DNA known as ________________
b) separates DNA strands
c) attaches nucleotides to form a strand of __________
Finish the RNA strand that would complement the following DNA strand:
DNA strand
CGTACCGATTAG
mRNA strand
GCA
The Genetic Code
The mRNA strand is a code that’s read 3 nitrogen bases at a time. This set of 3 nitrogen bases is known
as a _____________. Each codon matches a specific _____________________.
Translation
RNA
Protein
Translation is the process of using the new mRNA as instructions to show which order the amino acids
should go in. This happens in the __________________ of the cell. The order of the amino
acids determines the type of protein that is made!