Forensic Science Exam 2

Chps 13 + 14

Absorption, Distribution, Elimination

What are the 3 stages of alcohol in the human body?

30-90

For an average human drinking on an empty to modestly full stomach, alcohol is absorbed entirely into bloodstream ______ minutes after completion of drinking

2-4

When drinking on a full stomach, the absorption time can be as long as ____ hours

longer; lower

The _____ the time for complete absorption to occur, the _____ will be the peak alcohol in the blood for a given number of drinks

Brain, cerebrospinal fluid, vitreous humor

What are other watery portions of the body that can be used to determine alcohol levels if blood is not available?

Oxidation and Excretion

What 2 processes help accomplish elimination of alcohol throughout the body?

Oxidation

• Takes place almost entirely in liver'

• Enzymes convert alcohol first to acetaldehyde, then to acetic acid, then converted into carbon dioxide and water

• The 2 enzymes are called alcohol dehydrogenase and aldehyde dehydrogenase

5%

What percentage of alcohol is excreted unchanged in the breath, urine, and perspiration?

0.10%

If blood alcohol concentration is defined as percent weight per volume, then what is the BAC equivalent to 0.10 grams per 100 milliliters of blood?

0.015%/hr

Although it varies, what is the reasonable average of the elimination or “burn-off” rate of alcohol?

Blood concentration

Experimental evidence has verified that the amount of alcohol exhaled in the breath is in direct proportion to the ____________ and is directly proportional to alcohol in brain

0.08%

What is the current legal measure of BAC for drunk driving?

2100 : 1

What is the ratio of alcohol in the blood compared to alcohol in alveolar breath?

No

Are portable, handheld, roadside breath testers used to determine a preliminary breath-alcohol content admissible in court proceedings as proof of intoxication?

Gas Chromatography

What method of testing offers a toxicologist the most widely used approach for determining alcohol levels in blood in forensic labs?

anticoagulant; preservative

Once removed from body, blood is best preserved when sealed in an airtight container after an ______ and a ________ have been added and stored in a refrigerator

Decline

Failure to properly preserve blood removed from living individuals may result in a _____ of the blood alcohol level

Implied Consent Law

• A law that every state has adopted to prevent a refusal to take a test for alcohol consumption

• Law states that the operation of a motor vehicle on a public highway must either consent to a test for alcohol consumption, or lose their license for some designated period

Schmerber v. CA

What court case resulted in the Supreme Court deciding that the taking of blood samples was not protected by the 5th amendment?

MO v. McNeely

Court case where Supreme Court ruled that police should obtain a search warrant prior to the drawing of a person’s blood for alcohol testing

Screening and Confirmation

What are the 2 steps for identifying abused drugs?

Gas Chromatography

Thin-Layer Chromatography

Immunoassay

What are some of the most widely used screening tests?

Gas Chromatography/Mass Spectrometry (GC/MS)

What test is generally accepted as the confirmation test of choice?

True

The concentration of a drug in urine is a poor indicator of influence from drug, but is stronger as evidence showing previous use

Hair

What part of the body can be used as a historical marker for delineating drug intake as it continues to grow?

Carbon Monoxide

What is one of themost common poisons encountered in forensic labs?

3-5 months

It usually takes how many months in a training program for an officer to be certified as a drug recognition expert (DRE)?

Trace Elements

Many manufactured products and even most natural materials contain small quantities of elements that are present in concentrations of less than 1%. These elements can provide “invisible” markers that may establish the type and source of origin of a material

Emission Spectrograph

Vaporizes and heats samples to a high temperature so that the atoms present in the material achieve an “excited” state, which will emit light

The energy difference between 2 orbitals

In the equation E = hf, what is the meaning of E?

A universal constant; Planck’s constant

In the equation E = hf, what is the meaning of h?

Frequency

In the equation E = hf, what is the meaning of f?

Inductively Coupled Plasma Emission Spectrophotometry (ICP)

The sample, in the form of aerosol, is introduced into a hot plasma, creating charged particles that emit light of characteristic wavelengths corresponding to teh identity of the elements present

• Alpha Particles

• Beta Particles

• Gamma Rays

Unstable nuclei undergo radioactive decay by emitting?

Alpha Particles

2 protons + 2 neutrons

Beta Particles

Electron emitted when neutron converted to proton

Gamma Rays

High energy electromagnetic radiation

Automobile

______ manufacturers normally apply a variety of coatings:

• Electrocoat primer (black to gray)

• Primer surfacer (various polymers and colors)

• Basecoat (main color pigments dissolved in polymer, possibly with metal oxides or aluminum flakes)

• Clearcoat (various clear polymers)

Pyrolysis Gas Chromatography and Infrared Spectrophotometry

What are 2 invaluable techniques for distinguishing most paint binder formulations, adding more significance to forensic paint comparison?

True

When a transfer of paint occurs in hit-and-run situations uncontaminated reference paint must always be collected from an undamaged area of the car that’s in close proximity to the damaged area

Paper druggist folds, glass or plastic vials

Which containers are the best choice for paint?

1,000

There are over how many distinguishable soil colors?

Forensic Geologists

These officials will characterize and compare the mineral content of soils

100

Standard/Reference soils are to be collected at various intervals within a ____ foot radius of teh crime scene, as well as the site of the crime, for comparison of the questioned soil