Crj 5150: Criminalistics Final Exam

Front 1

What were the three major innovations of the Bertillon (Anthropometry) system? (Be able to describe them)

Back 1

1. Standardized the terminology of identification.
2. Standardized the full-face and right profile in mugshots.
3. Developed a system of body measurements that could be indexed and retrieved later.

Front 2

What are the characteristics of an ideal Personal Identification (Biometric) system?

Back 2

1. Useful throughout an entire lifetime.
2. Robust; Difficult to lose accidentally.
3. Difficult to alter intentionally.
4. Easily indexed and retrieved.
5. Highly Individual.
6. Repeatable and Reliable.
7. Useful for all people.
8. Universal format for all law enforcement agencies.
9. Fast and easy to use.

Front 3

How many 'points' of comparison are required in order to state that a questioned and knon fingerprint came from the same source? (Explain)

Back 3

No minimum. The only standard is the examiner's judgment.

Front 4

Are fingerprint powders used to process porous or nonporous surfaces? Is chemical processing (iodine, ninhydrin, etc.) used for porous or nonporous surfaces? Explain the difference.

Back 4

Fingerprint powders are used for nonporous surfaces (surfaces that do not absorb sweat).

Chemical Processing is used for porous surfaces. (Materials that absorb sweat i.e. paper).

The difference between the two depends on what else is present in the evidence.

Front 5

Understand glass-fracture. Be able to determine the direction from which a piece of glass was broken.

Back 5

4 R Rule.

Ridges along
radial-fracture lines form
right-angles to the
rear (opposite of where the force originated).

Front 6

Be able to discuss the individuality of trace evidence: whether there are ever situations when an item of trace evidence can be matched back to a single source. (Why/ why not?)

Back 6

There are situations when an item of trace evidence can be matched back to a single source. Things like rare soil, or other biological materials. On the other hand, things like carpet fibers are not as conclusive because many people might have that same carpet or it might be mass-produced.

TLDR: It depends on the evidence.

Front 7

What is the fire triangle?

Back 7

Fuel, Heat (Spark), and Oxygen (Oxydizer).

Front 8

What types of evidence are best-suited to link a suspect to an arson or explosives incident?

Back 8

The best evidence to link the suspect to the scene is that evidence which can survive a fire/explosion. Most often that is tool-mark evidence. Tool marks may be left behind the manufacture of timers, detonators, ignition devices, etc.

Front 9

Difference between high and low explosives. (Definitions and the difference in effects)

Back 9

High Explosive: Caused to explode by physical shock, spark, etc. Not the explosive to damage, used to cause that material to explode. Very sensitive to shock and disturbances.

Low Explosives: Burn rapidly, do not detonate unless contained, require some sort of ignition (i.e. fuse or spark) in order to start decomposing. Does damage.

Front 10

Why must low explosives be placed inside a container (e.g.pipe) in order to explode?

Back 10

Material is not able to detonate on its own.

Front 11

Method Question:

Given a suspected arson scenario, explain your method to search, document, collect and package the evidence. (This is a potential essay question, so be detailed) Explain your thought process. What would you hope to prove or disprove from evidence collected?

Back 11

First evidence is documented (ideally while the fire is still in progress). Then, the point of origin is determined (if possible). Then the ignition device/source is collected.

Front 12

Describe measures tha tmay be necessary to fingerprint a body found underwater. Describe measures for a body found in the desert.

Back 12

Desert- Skin on fingertips will need to be rehydrated.
Underwater- Skin on fingertips will need to be dehydrated.

Front 13

The difference between presumptive (screening) and confirmatory tests. Why is it important to do both (if possible)?

Back 13

Preliminary (Presumptive/Screening)- Test to see if something is present. Less expensive than confirmatory tests.
Confirmatory Tests- Proves that material being tested for is actually present.

It is impoirtant to do both because the preliminary test might be a false positive.

Front 14

For the different DNA methods, you can refer to them by their abbreviations (RFLP, STR, PCR, mtDNA). You do not need to explain in detail how they work, but should understnad what they do, and/or what is special about that particular method.

Back 14

RFLP- Genetic Fingerprinting via genome mapping. (Inexpensive)
STR- Easy, stable and predictable data with higher power of discrimination. Used to identify people.
PCR- Generating up to millions of copies of a DNA sequence out of a single or a few copies of a piece of DNA.
mtDNA- USed for human ideentification in degrated samples that lack nuclear DNA (ex: hair, bone and teeth).

Front 15

Know the questions that can be answered by blood spatter evidence (angle of impact, direction of travel, etc.)

Back 15

Higher the height, larger in diameter the drop will be up to 6 or 7'. Thick part of the drop, if dropped at an angle, will point to the point of origin.

Front 16

Modern DNA methods are dramatically more sensitive (~250x> 1985). Name an advantage and potential disadvantage (or difficulty) to this increased sensitivity.

Back 16

An advantage of DNA methods being dramatically more sensitive is that it can narrow down evidence to a specific person with a high percent chance of being accurate. A disadvantage or difficulty due to this increased sensitivity are false positives.

Front 17

Method Question:

Given a scenario with bodily fluid evidence, describe how you would sesarch for, collect and package that evidence.

Back 17

Wet blood= Dry Swab
Dried Blood= Swab moistened with distilled water.

Bloody items must be dried as quickly as possible and stored in paper.

Front 18

Give a short definition (1 or 2 sentences) for absorption, distribution, Metabolism, and Excretion.

Back 18

How drugs are processed through the human body. Absorbed through the bloodstream, distributed to different compartments in the human body, metabolixed and broken down changing chemistry of the drug to facilitate removal and excreted through the kidneys (urine, feces, perspiration, hair, etc.