8/9/2019 (4) Explosives

1/12

THE FORENSICS OF BOMBS

A material which can undergo a self-sustaining

chemical reaction which gives off heat, rapidly

releasing a large amount of energy

Rapid - decomposition can occur in

fractions of a second

Reactions turn solids and liquids into

superheated gases almost instantaneously

A material which can undergo a self-sustaining

chemical reaction which gives off heat, rapidly

releasing a large amount of energy

Rapid - decomposition can occur in

fractions of a second

Reactions turn solids and liquids into

superheated gases almost instantaneously

ENERGETIC MATERIALENERGETIC MATERIAL

FORMS OF ENERGY RELEASEFORMS OF ENERGY RELEASE

HeatHeat

LightLight SoundSound

8/9/2019 (4) Explosives

2/12

TYPES OF ENERGETIC MATERIALTYPES OF ENERGETIC MATERIAL

Pyrotechnics

Propellants

Explosives

Pyrotechnics

Propellants

Explosives

PYROTECHNICSPYROTECHNICS

PURPOSE:

Create Smoke, Light, and Heat

EXAMPLES:

Display Fireworks

Road Flares

Smoke Grenades

Thermites

PURPOSE:

Create Smoke, Light, and Heat

EXAMPLES:

Display Fireworks

Road Flares

Smoke Grenades

Thermites

PROPELLANTSPROPELLANTS

PURPOSE:

Produce Controlled Gas Release

EXAMPLES:

Black & Smokeless Powder, Rocket

Fuel

PURPOSE:

Produce Controlled Gas Release

EXAMPLES:

Black & Smokeless Powder, Rocket

Fuel

8/9/2019 (4) Explosives

3/12

Propellants or Low Explosives

Pyrodex - BP Substitute

Black Powder

KNO3, C, S

Smokeless Powder

Examples of High

Explosives:

Dynamite

C-4

TNT

ANFO

EXPLOSIONEXPLOSION

It seems unnecessary to define explosion, for

everyone knows what it is-

It seems unnecessary to define explosion, for

everyone knows what it is-

A loud noise and the sudden

going away of things from the

place where they have been.

A loud noise and the sudden

going away of things from the

place where they have been.

8/9/2019 (4) Explosives

4/12

EXPLOSIVE EFFECTSEXPLOSIVE EFFECTS

EXPLOSIVE EFFECTSEXPLOSIVE EFFECTS

Effects of Explosions

Primary Fragmentation - Originates From the Device Itself

Secondary Fragmentation - Items in Close Proximity to the

Device (rocks, glass, etc )

FRAGMENTATION EFFECT

8/9/2019 (4) Explosives

5/12

Effects of Explosions

INCENDIARY or THERMAL EFFECT

Effects of Explosions

Blast Effects

Positive Pressure Phase/Shock Wave

Negative Pressure Phase

Ears do not Rip Off Heads

Bodies Disassemble at ~ 350 psi

Heads are Well Made & Rugged

Van Gogh Effect

8/9/2019 (4) Explosives

6/12

Low Velocity Propellant (Good for Black

Powder)

Even 6 7 thousand fps way too high

IMPOSSIBLE TO ESTIMATE ON SITE

Low Velocity Propellant (Good for Black

Powder)

Even 6 7 thousand fps way too high

IMPOSSIBLE TO ESTIMATE ON SITE

6-7,000 feet/sec. ?6-7,000 feet/sec. ?

WHAT IS AN IED?

A Device Comprising Commercially Available

or Homemade Components in Conjunction with

Explosive Material Designed to Function

Unconventionally

IED COMPONENTS

- Power Source:

Battery, Capacitor

- Conductor:Electrical Wiring

-Switch:

Mousetrap, Magnetic Reed Switch

- Load:

Explosive/Incendiary Material

8/9/2019 (4) Explosives

7/12

TYPES of IEDs

Mail Bombs

Large Vehicle Bombs

Command Detonated

Roadside IED

Bomb Components

What Survives?

Pieces of the Container

Bomb Components

What Survives?

Pieces of the Container

Forensic Evidence

8/9/2019 (4) Explosives

8/12

Oklahoma City Bombing

SCENE PERIMETERS

8/9/2019 (4) Explosives

9/12

Evidence Recovery

Rear axle of a truck

with a CVIN

Replica of the Ryder Truck

Ignition key for a

Ford vehicle recoveredbehind the YMCA

No Clue too Small

8/9/2019 (4) Explosives

10/12

CHARGE SIZE

DEVICE COMPONENTS

Evidence Recovery

White and blue plastic

fragments

Recovered from

rooftop of the Journal

Records Building and

the Murrah Federal

Building

8/9/2019 (4) Explosives

11/12

8/9/2019 (4) Explosives

12/12

Search of Nichols Home

Toolmark identification of drill

bit with the hole in the lock fromthe Martin Marietta quarry theft

CHEMICAL TRACE EVIDENCE