DERMAL NITRATE TEST PARAFFIN TEST METHOD Molten paraffin

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DERMAL NITRATE TEST ( PARAFFIN TEST ) METHOD: • Molten paraffin wax is brushed

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

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,

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.

BALLISTICS - SPECIAL ASPECTS • • Balling of shots Bullet embolism Billiard ball effect

BALLISTICS - SPECIAL ASPECTS • • Balling of shots Bullet embolism Billiard ball effect Ricochet bullet

Various types of bullets • • • Tandem bullet Tandem cartridge Souvenir bullet Frangible

Various types of bullets • • • Tandem bullet Tandem cartridge Souvenir bullet Frangible bullet Yawing bullet Tumbling bullet

• • Dum dum bullet Explosive bullet Incendiary bullet Plastic bullet

• • Dum dum bullet Explosive bullet Incendiary bullet Plastic bullet

• • • Single entry, multiple exits Entrance wound present, bullet not found

• • • 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

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 • • • Crime scene Clothing Firearm injuries Precautions Cause of death

Autopsy procedures • • • Crime scene Clothing Firearm injuries Precautions Cause of death Chemical analysis

SUICIDE HOMICIDE • More common in • Can involve either males sex • Usually

SUICIDE HOMICIDE • More common in • Can involve either males sex • Usually single wound • Usually multiple. • Injury in one of the sites- temple, centre • Can be anywhere of forehead, roof of (inaccessible areas & mouth, left side non-vital areas). chest.

• • SUICIDE Usually contact wound. Weapon near the body Scene – victim’s

• • 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

THANK YOU

THANK YOU