PCC 274 Exam 3 (Ch 10, 11, 16, 17, Bundy + microscope)

A compound microscope is equipped with two objective lenses (10x and 45x) and has a 10x ocular lens. The highest magnification attainable with this instrument is:

450x

In order to examine an opaque object with a compound microscope, one must

Use REFLECTED illumination

Which microscope is best suited to the study of birefringent minerals and fibers?

Polarizing

A transparent specimen is viewed through a microscope using _________ light while an opaque object requires _________ illumination.

Transmitted; Vertical

[T or F] - The stereoscopic microscope has a narrow field of view

False

[T or F] - As magnifying power increases, the microscope's field of view also increases.

False

[T or F] - The infrared microspectrophotometer is used to analyze fibers and paints.

True

[T or F] - The lens nearest the specimen is called the ocular lens.

False

[LA] Briefly describe how a comparison microscope works and what it is used for.

Two microscopes linked by an optical bridge that allow an observer to view two independent images in one field, each from a separate objective for comparison

A comparison microscope is used for comparing samples against one another, to closely examine markings made from interaction with a firing pin, rifling, etc.

Short tandem repeats (STRs) targeted for routine DNA casework belong to the

nuclear genome

The number of short tandem repeat (STR) loci required to be typed for forensic DNA casework in the United States is

20

The refractive index of a substance varies with

Its temperature

The wavelength of the light passing through it

The color of the light passing through it

From our lecture, Laser stands for

Light amplification by stimulated emission of radiation

What are the two main types of DNA variation?

1. Mitochondrial polymorphism

2. Nuclear polymorphism

What is the main ingredient in ordinary glass?

Sand

Which of these states did Ted Bundy kill his victims in?

Washington, Oregon, Colorado, Utah, and Florida

If an object is immersed in a liquid of greater density, it will:

Float

Arson investigators must work quickly to collect evidence at a fire scene because:

Accelerant residues may quickly evaporate

Safety requirements may require that cleanup and salvage operations begin quickly

Accelerants in soil may rapidly degrade

In current practice, simultaneous separation of multiple STR loci on a capillary electrophoresis instrument is achieved by:

Differences in the fluorescent dye associated with STRS

Differences in the amplified STR lengths

A fuel can only achieve combustion in:

The gaseous state

CODIS, the national DNA database of short-tandem repeats profiles:

Was created in 1994 and each state/territory uploads profiles from convicted offenders

Does not permit searching of victim profiles

Is maintained at a national level by the FBI

The presence of three peaks (alleles) for at least one short tandem repeat (STR) locus in a profile indicates the sample is:

From multiple sources/contributors

The four phases of a fire progression are (in correct order)...

1. Incipient

2. Emergent Smoldering

3. Free Burning

4. Oxygen-related Smoldering

Which chemical reaction is associated with a fire?

Oxidation

Which is NOT an intensive property of matter?

Weight

Which is an intensive property of matter?

Density

Refractive Index

Temperature

Movement of heat through a solid object is caused by:

Conduction

The process of a glass prism separating sunlight into component colors is called:

Dispersion

What is NOT true about primary explosives?

They are very stable

What is true about primary explosives?

They will detonate violently

They. are. used in blasting caps

They are very unstable

Examples) Lead azide and lead syphnate

What information can Quantitative PCR (qPCR) provide?

Amount of DNA

Quality of nuclear DNA

NOT: Detection of STR, DNA profile match

Which is a homemade explosive that has been used by terrorist organizations in the Middle East?

TATP

Which is a chemical used to synthesize the explosive TATP?

Hydrogen Peroxide

and Acetone

(Triacetone triperoxide)

Pigment granules that impart hair with color are found in the:

Cortex

A Low explosive has a velocity of detonation less than:

1000 meters per second

A High explosive has a velocity of detonation of

1,000 - 8,500 meters per second

Detonate almost instantaneously

Primary Explosives are:

Ultra-sensitive to heat, shock, or friction

Provide the major ingredients found in blasting caps or primers used to detonate other explosives.

Secondary Explosives are

Relatively insensitive to heat, shock, or friction

Will normally burn rather than detonate if ignited in small quantities in the open air.

The following chemical structure represents the ________ explosive.

C9H18O6

H3C / CH3 / O

TATP (Triacetone triperoxide)

The medullary index of human hair is _________ the medullary index for most other animals.

Less than

For our lectures, IMS is an acronym that means:

Ion Mobility Spectrometry

In determining whether a hair sample originated from a male or a female, the MOST important consideration is:

The results of DNA analysis performed on the root structure

Evidence collection of fire debris is collected in

Paint Cans

What's the amount needed for traditional DNA typing?

1 ng

A fiber whose microscopic appearance includes being ribbon-like in shape (flat) with twists at irregular intervals is:

Cotton

The Anagen phase will last:

About 6 years

What are the four basic methods of heat production?

1. Electrical

2. Mechanical

3. Nuclear

4. Chemical

Nuclear DNA typing can be most successfully accomplished on hairs that have been removed during which stage of growth?

Anagenic

DNA is a:

Polymer

The PCR technique requires the use of a thermal cycler to:

Copy DNA

[T or F] - Plastic bags are suitable to store evidence suspected of containing explosive residues.

False

[T or F] - A search of the fire scene must focus on finding the fire's point of origin.

True

[T or F] - Bombs made of High explosives must be detonated by an Initiating Explosion.

True

[T or F] - Secondary explosives are ultra-sensitive to heat.

False

[T or F] - Individual hairs can show variable morphological characteristics within a single individual.

True

[T or F] - Backdraft occurs at an explosive rate duet to the extreme temperatures being fueled by the new oxygen.

True

[T or F] - A first step in the forensic examination of fibers is to compare color and diameter.

True

[T or F] - Ted Bundy escaped from prison three times.

False

[T or F] - Mitochondrial DNA is used tot identify an individual with very high probability.

False

[T or F] - The boiling point of a substance is a chemical property.

False

[T or F] - It is possible to estimate when hair was last bleached or dyed by microscopic examination.

True

[T or F] - Ted Bundy's mother believed that Ted was innocent even after his execution.

True

[LA] Define intensive property and name two intensive properties of matter.

Intensive properties do not depend on the quantity of matter -- Value does not depend on the amount of the substance for which it is measured.

Examples include

1. Density

2. Refractive Index

3. State of matter

4. Temperature

[LA] Describe the flotation method and explain what it is used for.

Used to find/compare the density of glass. In the flotation method, a glass

particle is immersed in a liquid.

The density of the liquid is carefully adjusted by the addition of small amounts of an appropriate liquid (mixture of bromoform and

bromobenzene) until the glass chip remains suspended in the liquid

medium.

At this point, the glass will have the same density as the liquid medium and can be compared to other relevant pieces of glass which will remain suspended, sink, or float.

[LA] Give two similarities between Ted Bundy and John Wayne Gacy

1. Both had familial issues:

- Bundy: the woman he had been led to believe was his sister was truly his mother.

- Gacy: all his life, his father had deprived him of love and affection.

2. Sexual motives

- Bundy: would often sexually molest/rape his victims before, during, or after killing them.

- Gacy would sexually molest/rape his victims too.

[LA] Give two differences between Ted Bundy and John Wayne Gacy

- Bundy crossed states from Washington, Oregon, Colorado, Utah, and Florida.

- Bundy murdered young women with brown, middle-parted hair.

- MO - stabbing

- Gacy operated mostly in the Chicago/Cook County/Midwest area.

- Gacy murdered young men.

- MO - tourniquet and strangling

[LA] Name three techniques used for the elemental analysis of glass (abbreviations are accepted) .

1. Scanning Electron Microscopy with an Energy

Dispersive Spectrometer (SEM - EDS)

2. X- Ray Fluorescence Spectrometry (XRF)

3. Inductively Coupled Plasma Optical Emission

Spectrometry (ICP - OES)

4. Inductively Coupled Plasma Mass Spectrometry

(ICP - MS)

5. Laser Ablation (LA) Inductively Coupled

Plasma Mass Spectrometry (ICP - MS)

6. Laser Induced Breakdown Spectroscopy (LIBS)

[LA] Describe Ted Bundy MO and how he was arrested?

Bundy targeted brunette, petite Caucasian women aged 12 to 26 years old.

His method of obtaining the victims varied:

- Bundy would burglarize victim's homes and bludgeon them in their sleep, sometimes he would use an elaborate ruse, and sometimes he merely relied on his looks alone.

- Bundy would sometimes use a ruse to capture his victims.

- A fake cast, a sling, or use crutches to play on a potential victim's sympathy.

- He would ask them for the assistance of some kind, such as helping him put something in his car or asking for directions.

Victims were then struck in the head with a crowbar, shoved into his car, and forced to wear handcuffs.

His initial attacks involved him raping them (either with incidental objects found in the victim's bedroom or ones he brought with him) and then fatally bludgeoning them with a crowbar.

Before raping his victims, he would have them remove their clothing or take off his own clothing to prevent the authorities from finding any trace evidence.

He would later kill his victims by strangulation and would sometimes decapitate them post-mortem, keeping a few of their skulls as trophies.

In one case, he cremated the severed head of one victim in a fireplace.

Bundy would often visit his victims, whom he dumped at a site in Taylor Mountain. He admitted to applying makeup to the corpses, having sex with them, and would lie with them for hours afterward. He also dressed them in clothes that they never wore and apply nail polish that their families had never seen them use.

Bundy also kept a collection of photos of his victims that he took with a Polaroid camera as a way of remembering the crimes.

[SA] Mentioned in the documentary, what was unusual about Bundy's family life?

The women he has been led to believe was his sister was actually his mother.

[SA] What distinguishes an explosion from combustion?

The speed at which a reaction occurs.

Explosion - a chemical reaction that produces heat and gases rapidly in an instant.

Combustion - a chemical reaction that produces heat and gases slowly for a certain time period.

[SA] Name three ways that DNA typing have been used.

1. Forensic Cases

- matching suspect with evidence

2. Paternity tests

- identifying father

3. Mass disasters

- putting pieces back together

4. Historical investigations

- confirmation of an artifact belonging to individual

5. Convicted felon DNA databases

- determining identity of unknown criminals