1. FORENSIC PATHOLOGY
ELECTROCUTION

2. ELECTROCUTION Virtually all accidents Alternating currents
Most common type found in homes in the US
Low (<600 V)
High (> V)
Amperage is most important factor in the current flow
A = V/R

3. ELECTROCUTION Voltage Household – 110V High voltage lines – 8000 V
Must directly touch electrical circuit
Death mainly by ventricular fibrillation
High voltage lines – 8000 V
Electric current may jump (arc)
Death mainly by electrothermal injury or respiratory arrest

4. ELECTROCUTION Resistance Mainly by skin
Dry skin has resistance of 100,000 ohms
Dry calloused skin has resistance of 1,000,000 ohms
Moist skin has resistance of 1,000 ohms
Wet skin has resistance of 100 ohms

5. Mechanism of Death Minimal perceptible amperage = 1mA
5 mA will produce tremors in muscle
15 mA causes contractions
50 mA causes respiratory paralysis and death
75 mA causes ventricular vibrillation
1 A causes ventricular arrest

6. ELECTROCUTION Judicial execution High voltage currents Produces
3rd degree burns
Brain temperature up to 63°C

7. ELECTROCUTION Electroconvulsive “shock” Therapy
May cause fracture of bones
Due to muscle contractures
Most common are T12 and L1 vertebrae along with scapular fractures bilaterally

8. ELECTROCUTION Muscle Contraction Back and neck arch backward
Arms rotate inward, elbows flex and hands form fists
Hips and knees lock straight and feet extend
Individuals may grasp and continue to do so

9. ELECTROCUTION Autopsy Findings High Voltage Low Voltage
Electrical burns over body
Low Voltage
Electrical burns at point of entry or exit
May have no electrical burns if minimal resistance to flow
Bathtub
Muscle Contraction

13. ELECTROCUTION Low Voltage Burns
Most often on palms of hands and tips of fingers
Erythematous or blistering
Chalky white lesions
Raised borders with central crater
Yellow or black discoloration at burn site

14. ELECTROCUTION
A typical electrical burn consists of a round, oval or elongated crater.
Base of wound is dark brown.
Ridge of elevated skin on margin

15. ELECTROCUTION

16. ELECTROCUTION
If victim survives for short period of time after contact there may be a collection of foam in air passages.

17. ELECTROCUTION High Voltage Burns Charring of body
Current runs through intermediary object
Burns are large and irregular
Chalky white
Raised borders and central crater
Yellow black discoloration at burn site
Massive tissue destruction
Organ rupture

20. ELECTROCUTION Manner of Death Usually all accidental
May be sexual in nature
Suicides and homicides are rare
Ground-Fault Current Interrupters (GFCI)
Circuit is broken if amperage increases by 5 mA

21. ELECTROCUTION Lightning Charged undersurface of a thunder cloud
Virtually always Negative
Electrical charge to the ground
Direct Strike
May injure or kill person
Side flash
Hits an object and ricochets

22. ELECTROCUTION Side-Flash Strike
Clothing torn, shoes burst, hair seared, burned on skin from zipper or other metal objects
Entrance and exit burns
Rupture of tympanic membrane
Death by cardiopulmonary arrest or thermal injury
Injury to cardiac and respiratory centers of brain

23. ELECTROCUTION Aborescent Lightning injury Fern-like pattern
Lichtenberg figures
Appears within 1h of lightning injury and fades within 24h
Not burns
May be due to a positively charged lightning bolt
May be due to flashover by positive discharge over skin
Really don’t know what causes this pattern