Nitro Dermal Test

Introduction There are different method for Identification of a shooter by detection of gun shot residues on the hands. There are unburnt propellant grains& metallic elements which originate from primer ,propellant & projectiles as gunshot residues when firearm is fired. These residues are tested & pattern deposited is determined to find out whether the suspect has discharged a firearm.

Procedure Of Test. The molten paraffin is applied on the hands of shooter & then it is peeled off. If propellant particles are present it gets embedded in paraffin. Solution of diphenylamine or diphenyal benzidine in Sulphuric acid is poured over the cast blue color indicates the presence of nitrate. This has been discontinued as it is positive for a person who has passed urine or worked with fertilizers. The modern instrumental methods used for examination of hand swabs /washing are neutron activation analysis ,Atomic absorption ,Scanning Electron Microscopy with X-ray analysis are used.