FSC239Y5 Lecture Notes - Lecture 1: Gunshot Residue, Barium Nitrate, Scanning Electron Microscope
Document Summary
What is gunshot residue: particles that contain all three elements; lead, barium, antimony, pb, ba, sb, typically spherical, about 1-10 um, finer than a hair. We are actually looking for residues of the primer. Contains: instructions, questionnaire, gloves, 2 cfs seals, and 2 pairs of sampling stubs. Sampling stub: 1 inch diameter, aluminum stub covered with double sided tape. Gsr collection kit: 4 stubs are collected per suspect, 2 from each hand back of hand (wrist to knuckles), not palm because of sweat, web and back of hand. Positive results numbers: typically find 5 or few gsr particles (pbbasb) from a hand kit, cases involving garments are highly variable. Meaning (goes into report, 3 options): fired a gun, was near the gun when it fired, touched a surface with fsr on it. Negative result meaning: didn"t fire a gun, gun didn"t deposit gsr on the hands, gsr was lost due to activity, sampling was ineffective (did not catch gsr)
