AIIMS 2017

Atropine is not an antidote in:

A person is criminally not responsible for his actions if at the time of doing it by reason of unsoundness of mind, in incapable of knowing the nature of the act or that he is doing what is either wrong or contrary to the law.

A middle aged lady was found in a robbed room lying in a pool of blood on forensic examination there was an entry wound of size around 2 x 2 cm on the left temporal region with tattooing and blackening around the wound. There was also an exit wound with beveling at the right temporal region. On fuher examination two bullet fragments were found inside the brain parenchyma. Which of the following could be used to determine the distance from which the weapon was fired?