Question:medium
Gun powder residue on clothing can best be visualized by?
Gun powder residue on clothing can best be visualized by?
Show Hint
Which rays can see through dark, blood-stained cloth to show the powder?
Updated On: Jun 24, 2026
- Magnifying lens
- UV rays
- Infrared rays
- Dye
Show Solution
The Correct Option is C
Solution and Explanation
This question tests the forensic technique for revealing firearm residue on garments. After a shot, partially burnt and unburnt propellant settles on the clothing as soot and a stippled powder pattern, but on dark, soiled or blood-soaked cloth these deposits are effectively invisible.
The solution lies in the physics of infrared light. Infrared rays pass through superficial blood and dark dyes that absorb visible light, while the carbonaceous powder grains absorb and contrast against the fabric. Photographing the area with infrared film therefore makes the powder tattooing and soot ring stand out clearly, which also helps the examiner judge the firing distance.
Considering why the others fail: a magnifying lens merely magnifies and cannot uncover concealed particles, ultraviolet light is reserved chiefly for detecting biological fluids like seminal stains, and a dye test is a chemical reaction rather than the routine imaging method asked for here. Hence infrared imaging is the answer.\[\boxed{\text{Infrared rays}}\]
The solution lies in the physics of infrared light. Infrared rays pass through superficial blood and dark dyes that absorb visible light, while the carbonaceous powder grains absorb and contrast against the fabric. Photographing the area with infrared film therefore makes the powder tattooing and soot ring stand out clearly, which also helps the examiner judge the firing distance.
Considering why the others fail: a magnifying lens merely magnifies and cannot uncover concealed particles, ultraviolet light is reserved chiefly for detecting biological fluids like seminal stains, and a dye test is a chemical reaction rather than the routine imaging method asked for here. Hence infrared imaging is the answer.\[\boxed{\text{Infrared rays}}\]
Was this answer helpful?
0
