2. 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.
3. 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.
4. Other tests
OTHER TESTS (To find out whether a suspect
discharged a firearm recently, or not) are:
• The Harrison & Gilroy test
• TLC, HPLC, GC.
• Atomic absorption spectroscopy.
• Neutron activation analysis.
5. BALLISTICS - SPECIAL ASPECTS
• Balling of shots
• Bullet embolism
• Billiard ball effect
• Ricochet bullet
6.
7. Various types of bullets
• Tandem bullet
• Tandem cartridge
• Souvenir bullet
• Frangible bullet
• Yawing bullet
• Tumbling bullet
8. • Dum dum bullet
• Explosive bullet
• Incendiary bullet
• Plastic bullet
9. • Single entry, multiple exits
• Entrance wound present, bullet not found
• Unexplained bullets in body
• Atypical wound of entrance
• Multiple entry/exits (single shot)
10.
11. 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.
12. Autopsy procedures
• Crime scene
• Clothing
• Firearm injuries
• Precautions
• Cause of death
• Chemical analysis
13. SUICIDE
• More common in
males
• Usually single
wound
• Injury in one of the
sites- temple, centre
of forehead, roof of
mouth, left side
chest.
HOMICIDE
• Can involve either sex
• Usually multiple.
• Can be anywhere
(inaccessible areas &
non-vital areas).
14. 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
