Transcript Wound Balistics 4

DERMAL NITRATE TEST
( PARAFFIN TEST )
METHOD:
• Molten paraffin wax is brushed on the suspect’s
hand
• After hardening it is peeled off.
• The inner surface of the wax cast is then treated
with diphenylamine or diphenylbenzidine reagent.
• ‘ Blue colour ’ develops wherever the powder
residue is present.
DERMAL NITRATE TEST
( PARAFFIN TEST )
DRAWBACKS:
FALSE NEGATIVE RESULT
• Washed hand
• Delay in doing the test.
• Weapon is well constructed.
FALSE POSITIVE RESULT
• Hand contaminated with nitrogenous compounds –
Tobacco, leguminous plants, soil, cosmetics,
fertilizers etc.
Other tests
OTHER TESTS (To find out whether a suspect
discharged a firearm recently, or not) are:
• The Harrison & Gilroy test
• TLC, HPLC, GC.
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Atomic absorption spectroscopy.
Neutron activation analysis.
BALLISTICS - SPECIAL ASPECTS
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Balling of shots
Bullet embolism
Billiard ball effect
Ricochet bullet
Various types of bullets
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Tandem bullet
Tandem cartridge
Souvenir bullet
Frangible bullet
Yawing bullet
Tumbling bullet
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Dum dum bullet
Explosive bullet
Incendiary bullet
Plastic bullet
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Single entry, multiple exits
Entrance wound present, bullet not found
Unexplained bullets in body
Atypical wound of entrance
Multiple entry/exits (single shot)
Kennedy Phenomenon
• Medico-legal evaluation of firearm injury
made difficult by surgical suturing or
alteration.
Rayalaseema Phenomenon
• Medico-legal evaluation of a firearm injury
made difficult by deliberate mutilation. Eg.
Cutting or stabbing through it.
Autopsy procedures
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Crime scene
Clothing
Firearm injuries
Precautions
Cause of death
Chemical analysis
SUICIDE
HOMICIDE
• More common in
• Can involve either sex
males
• Usually single
• Usually multiple.
wound
• Injury in one of the • Can be anywhere
sites- temple, centre
(inaccessible areas &
of forehead, roof of
non-vital areas).
mouth, left side
chest.
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SUICIDE
Usually contact
wound.
Weapon near the
body
Scene – victim’s
home
Suicide note may
be present
HOMICIDE
• Close or distant
shot
• Weapon absent
• Anywhere
• Absent
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