Death And Explosions

Question 1

What is the OCME? What do they do?

Answer 1

Office of the Chief Medical Examiner, sends out medical investigators.

Question 2

What are the 5 categories of decomposition?

Answer 2

1. Autolysis - cell self digestion
2. Bloat - bacteria grows/reproduces/creates gases (Nitrogen/Methane) and liquid.
3. Active Decay - body loses much of its mass (maggots/bacteria/weather), tissues liquify.
4. Advanced Decay - bones/hair/tendons left
5. Skeletonization - only bones and some connective tissue remain.

Question 3

What are autopsies? What happens?

Answer 3

Autopsy - methodical opening of the body to determine cause of death.

Xrays for objects
Weigh organs and their contents
Lungs + liver checked for possible drug use
Fingernails + sexual areas for evidence of fights and SA

Question 4

Causes of death

Blunt force trauma
Sharp force trauma (different between cuts and stabs?)
Asphyxia
Petechiae

Answer 4

Blunt force trauma - bonks

Sharp force trauma - cuts/stabs (stab wound is deeper than it is long)

Asphyxia - choking/suffocating/lack of O2 (ligature marks)

Petechiae - pinpoint haemorrhaging (eyes/face/chest)

Question 5

Manners of death

Homicide
Suicide
Accidental
Natural
Undetermined

Answer 5

Homicide - gross negligence, reckless or intentional actions of another person
Suicide - taking their own life
Accidental - unintentional harm through negligence
Natural - disease, toxins, environment
Undetermined - nothing else fits

Question 6

Time of death estimations

Algor mortis*
Livor mortis
Rigor mortis (beginning and end time?)

Answer 6

Algor - body cooling (not helpful because weather)
Livor - circulation stops and blood settles
Rigor mortis - body stiffens (24hrs - 36hrs)

Question 7

What are we looking for when investigating fire/explosion scenes? (4)

Answer 7

Causation (was it intentional?)
Source
Who/what caused it?
Type of explosives/accelerants

Question 8

What are the components of fires?

Answer 8

Combustion/heat/light/smoke.

Question 9

Define combustion and exothermique reactions

Answer 9

Combustion - substances and O2 combine and make heat/light/smoke

Exothermic reaction - chemical reaction that makes heat

Question 10

How is heat measured?

Answer 10

British thermal units - amount of heat needed to raise 1lb of water by 1 degree Fahrenheit

Question 11

What are the 3 requirements of combustion?

Answer 11

Fuel, O2, heat.

Question 12

How are samples from a fire scene collected and analyzed? Which area is focused?

Answer 12

Area of origin, stored in an UNLINED paint can, to lab for gas chromatograph.

Question 13

What does a gas chromatograph do? How?

Answer 13

Measures elements in gas, searches ignitable liquids reference connection (ILRC)

Question 14

Deflagration vs detonation?

Answer 14

Deflagration - rapid oxidation + low intensity pressure wave

Detonation - rapid oxidation + violent disruption/noise/shock wave

Question 15

Low vs high explosives? Primary vs secondary?

Answer 15

Low - black/smokeless powders, decompose quickly (<1000 m/s). For launching stuff (like bullets and fireworks)

High - TNT/PETN,RDX,dynamite. Almost instantaneous. Primary - ultra sensitive to heat/pressure (straight TNT). Secondary - not as sensitive, anything else.

Question 16

Definitions:

Heat transfer
Radiation
Convection
Accelerant

Answer 16

Heat transfer - heat moving through/between objects
Radiation - transfer of heat energy from hot to cool
Convection - transfer of heat energy of molecules in a fluid (liquid or gas)
Accelerant - anything used to start/speed/sustain a fire.

Question 17

What is the headspace technique for processing canned samples?

Answer 17

Poking hole in container basically

Question 18

Journaling questions of Lebanon explosion

How = type of explosives and explosion

Answer 18

What? Explosion in Beirut
Where? Harbor midway between port and central district, near water.
How? Detonation, probably with secondary high explosives.