Question

1. which of the following pairs of technologies and/or techniques is the best way to identify unknown accelerants in an arson fire?

a. gas chromatography and mass spectrometry
b. portable arson sampler and metal oxide sensors
c. accelerant detection dogs and criminal profiling
d. photoionization detectors and solid - phase microextraction

numeric response
indoor fire scene investigation tasks

1. evidence collection area is created
2. a detailed diagram of the site is drawn.
3. investigators try to determine the fire’s point of origin.
4. access to the fire scene is controlled by the police and the fire department.

1. the correct sequence of tasks that arson experts follow when investigating a fire scene include ____, __, __, and ____

description of burn patterns found at an arson scene

1. produced after a liquid accelerant is poured on a carpet and set on fire
2. ignitable liquid fuel that has absorbed and burned into wooden floor joists
3. produced as a fire moves up a vertical surface
4. dark - coloured burn patterns produced when a liquid accelerant burns on a nonporous surface

1. match each description numbered above with its correct burn pattern stated below:

definition:
burn pattern: classic v doughnut rundown ignitable liquid pour

Explanation:

Multiple - Choice Question (Question 10)

To identify unknown accelerants in an arson fire, we need accurate and detailed chemical analysis. Gas chromatography (GC) separates the components of a mixture, and mass spectrometry (MS) identifies the separated components by their mass - to - charge ratio. This combination is a standard and highly accurate method for analyzing chemical substances like accelerants. Portable arson samplers and metal oxide sensors are not as accurate for identifying unknown accelerants. Accelerant detection dogs are good for locating areas with accelerants but not for identifying the unknown accelerant chemically, and criminal profiling has nothing to do with the chemical identification of accelerants. Photoionization detectors are good for detecting volatile organic compounds but solid - phase microextraction is a sampling technique, and together they are not as effective as GC - MS for identifying unknown accelerants.

When investigating a fire scene, the first step is to control access to the scene (4) to ensure safety and prevent contamination of evidence. Then, a detailed diagram of the site is drawn (2) to document the scene. Next, investigators try to determine the fire's point of origin (3). Finally, an evidence collection area is created (1) to collect and preserve evidence.

1. "Produced after a liquid accelerant is poured on a carpet and set on fire" matches with "Ignitable Liquid Pour" because it describes the pattern formed when a liquid accelerant is poured and ignited.
2. "Ignitable liquid fuel that has absorbed and burned into wooden floor joists" - There is no specific burn pattern name given in the options that directly matches this, but if we consider the remaining patterns:
3. "Produced as a fire moves up a vertical surface" matches with "Classic V" as a fire moving up a vertical surface creates a V - shaped pattern.
4. "Dark - coloured burn patterns produced when a liquid accelerant burns on a nonporous surface" matches with "Doughnut" as the accelerant burning on a non - porous surface can create a circular (doughnut - like) pattern.

So the matches are:
1 - Ignitable Liquid Pour
2 - (No direct match from the given burn patterns, but if we assume a mis - labeling or a different approach, we can proceed with the remaining)
3 - Classic V
4 - Doughnut

Answer:

a. Gas chromatography and mass spectrometry

Numeric Response - Sub - Question 1 (Indoor Fire Scene Investigation Tasks)