Which of the following indicates unburned powder from a gunshot wound?

Tattooing or stippling is the correct choice as it specifically refers to the presence of unburned powder or gunpowder residue that is deposited on the skin when a gun is fired. This phenomenon occurs when a firearm is discharged at close range, where the expanding gases and small particles from the gunpowder are forcefully expelled from the muzzle, creating small, penetrating marks on the skin surface.

These marks appear as tiny red or dark spots, indicative of the unburned gunpowder that has come into contact with the skin. The presence of tattooing can provide important forensic evidence regarding the distance from which the shot was fired.

Pinpoint hemorrhages may occur due to the trauma of the bullet's passage or as a result of pressure from the gases; however, they do not indicate the presence of gunpowder residue specifically. Bruising can indicate blunt force trauma or impact but is also not exclusive to gunshot wounds or indicative of any residue. Thus, while all the options listed may relate to gunshot wounds in some context, tattooing or stippling uniquely points to the unburned powder aspect associated with a gunshot distance and technique.