Criminalistics exam 2

What would most strongly support the conclusion that a fire was intentionally set?

Presence of accelerant residues

What does the term flash point refer to in the context of controlled substances?

The lowest temperature at which a substance can vaporize to form an ignitable mixture with air

The autoignition temperature of a substance is defined as:

The temperature at which a substance will spontaneously ignite without an external spark or flame

Which type of evidence is most crucial for identifying the use of accelerants in suspected arson cases?

Residue analysis using Gas Chromatography-Mass Spectrometry (GC-MS)

The Harrison Narcotic Act of 1914 primarily aimed to:

Regulate and tax the production, importation, and distribution of opiates and coca products

Research on psilocybin significantly declined in the late 20th century primarily because:

Legal restrictions and its classification as a Schedule I controlled substance

Why are adulterants commonly added to illicit drugs?

To increase profit margins by adding bulk

Which adulterant causes necrotic wounds?

Xylazine

What is the primary purpose of chromatography in forensic science?

To separate and analyze the components of a mixture

What information does a chromatograph typically display?

The retention times and relative quantities of separated components

Which of the following is a key difference between Gas Chromatography (GC) and Liquid Chromatography (LC)?

GC is typically used for volatile, thermally stable compounds, while LC is better for non-volatile, thermally unstable compounds

Which of the following can help improve separation in Gas Chromatography (GC)?

Using a longer column with a smaller internal diameter

Which of the following was an unintended consequence of Prohibition?

The rise of illegal speakeasies and bootlegging

What was one of the earliest recognized medical uses of GHB?

Anesthetic and sleep disorder treatment

When analyzing botanical drug evidence, which part of the plant is most commonly used to identify marijuana (Cannabis sativa)?

Leaves and flowering tops

During an arson investigation, forensic chemists test fire debris for accelerants. Which of the following methods is the best for detecting ignitable liquids?

Gas chromatography-mass spectrometry (GC-MS) that identifies chemicals in the sample

What are the three essential components of the fire triangle?

Heat, fuel, oxygen

What does the flash point of a liquid indicate?

Lowest temperature to form ignitable vapor mixture

Which compound is an example of an alcohol?

Propanol

Which functional group is least likely to be polar?

Alkane

Which statement accurately describes benzene?

Delocalized π electrons contribute to stability

What was a major consequence of the Anti-Drug Abuse Act of 1986?

Created sentencing disparity between crack and powder cocaine

Why is cocaine still classified as Schedule II?

Accepted medical uses, high abuse potential

What was the consequence of the Harrison Narcotics Tax Act of 1914?

Limited legal access by requiring physician registration

Why was alcohol a staple in colonial diets?

Water quality was poor

Which amendment repealed Prohibition?

21st

In which condition were barbiturates commonly prescribed?

Anxiety, insomnia, epilepsy

What major concern arose with barbiturate use?

High risk of dependence and overdose

Which legislation placed barbiturates under stricter control?

Controlled Substances Act (1970)

What class of drugs replaced barbiturates for anxiety and insomnia treatment?

Benzodiazepines

What schedule do most benzodiazepines fall under?

Schedule IV

Why is GHB associated with sexual assault?

Induces sedation and memory loss in high doses

What schedule is GHB for medical use?

Schedule IV

Cocaine classification?

Schedule II

Reason for psilocybin research decline?

It was made illegal

Conditions studied with LSD/psilocybin?

PTSD, depression, and anxiety

First use of cannabis in the U.S.?

Industrial hemp cultivation for textiles and rope

Purpose of the 1937 Marihuana Tax Act?

To impose heavy regulations and taxes that effectively criminalized cannabis

Reason for cannabis being Schedule I?

The government determined it had no accepted medical use and a high potential for abuse

Proposition 215 significance?

Legalized medical marijuana in California

Common users of nitrous oxide?(poppers)

Young adults and partygoers in club and festival settings

Schedule II classification meaning?

High potential for abuse, with medical use under strict regulation

Why is fentanyl dangerous?

It is undetectable by most drug users and highly potent

Risk of xylazine as an adulterant?

Causes severe skin ulcers and necrosis

Caffeine’s role as an adulterant?

Increases stimulant effects and can mimic drug potency

Levamisole’s risk?

Suppresses the immune system and causes skin necrosis

Why is talc hazardous in drugs?

It can cause lung damage when inhaled and vascular issues when injected

Wavelength and frequency relationship?

Inversely proportional—when one increases, the other decreases

What does chromatography separation show?

Solubility differences

Purpose of presumptive tests?

Indicate the possible presence of a substance but require further confirmatory testing

What do GC-FID peaks indicate?

Different compounds in the sample

Key difference between GC and LC?

GC separation takes place at high temperatures

How to improve GC peak separation?

Decrease the carrier gas flow speed

Difference between random and systematic sampling?

Systematic sampling follows a fixed pattern or interval