What is the cause of entry-wound blackening in firearm injury?
In firearm injury, entry-wound blackening is due to the smoke produced by completely burned paicles coming out from the barrel of the firearm weapon. It is seen up to 30 cm from the firearm. Ref: Essentials of Forensic Medicine and Toxicology By Dr K S Narayan Reddy, 27th Edition, Pages 187-8, 190
Flame
Smoke
Hot gases
Unburned powder