Powder Tattooing
Definition
Stippling pattern of unburned and partially burned propellant grains embedded in the skin around an entry wound. Cannot be wiped off. Pathognomonic for the intermediate range; absent at contact (driven into wound track) and at distant (grains never reach the skin).
- Mark type
- Intradermal hemorrhagic punctate marks from propellant grain impact
- Range indicator
- Pathognomonic for intermediate-range gunfire
- Removability
- Cannot be wiped off; distinguishes from surface soot
Common questions
What exactly causes powder tattooing on skin?+
Unburned and partially burned propellant grains travel through the air and strike the skin at intermediate range. The impact abrades the superficial dermal layers, creating intradermal hemorrhagic punctate marks. These marks are the stippling pattern you see around an entry wound.
How is powder tattooing different from powder soot or fouling?+
Powder tattooing is caused by solid grains embedding themselves in the skin. Soot is surface deposit that can be wiped away. Tattooing cannot be removed by wiping because the grains have created actual dermal injury. This distinction is critical for determining whether cleaning could obscure the evidence.
What does the presence or absence of powder tattooing tell you about firing distance?+
Powder tattooing is pathognomonic for intermediate range. It is absent at contact range because unburned grains are driven into the wound track instead of striking the surrounding skin. It is also absent at distant range because the grains lose velocity and never reach the skin surface.
Related terms
- Modified Griess Test
- A contact-transfer colour chemistry test for nitrite-containing propellant combustion residue. Sulphanilic acid undergoes diazotisation with nitrous acid (from NO2 on the target...
- Soot (Blackening)
- Submicrometre carbon-rich particles from incomplete propellant combustion, deposited on the garment or skin surface around the entry hole at contact and near-contact...
- Azo Dye
- A class of organic dyes containing one or more azo groups (R-N=N-R'). Formed in the Griess test by coupling of a diazonium...
- Bullet Wipe
- Greyish to brownish ring of lubricant, lead and copper rubbed off the bullet onto the margin of an entry hole in clothing....
- Contact Shot
- Muzzle pressed against skin or clothing at the moment of firing. Hallmarks are a stellate (star-shaped) wound from sub-dermal gas tracking, a...
- Desensitisation (Griess Protocol)
- The step in the Modified Griess protocol in which background nitrite contamination (from sweat, atmospheric nitrogen, detergent) is removed from the garment...
- Lead-Free Primer
- A primer composition that omits lead styphnate, using DDNP or other compounds, producing no lead from the primer channel during discharge. Examples...
- Range of Firing
- The distance from the muzzle of the firearm to the target at the moment of discharge. Estimated from wound geometry, soot pattern,...
- Sodium Rhodizonate
- A chelating agent producing a scarlet-to-red colour with lead ions at acid pH. Applied to entry-wound margins and garment entry holes to...
- Sodium Rhodizonate Test
- Colour test for lead. The cloth is treated with sodium rhodizonate followed by buffer; lead deposits give a pink-to-red colour, confirmed with...
- Stippling
- Abrasion marks on skin or fabric produced by partially burned propellant grains exiting the muzzle with sufficient velocity to mechanically impact the...
- Test-Fired Control Panels
- Fabric panels fired at known, measured muzzle-to-target distances using the same or equivalent weapon and ammunition as in the case, processed with...
Explained in these topics
- Determination of Range of Firing in Firearm CasesStippling pattern of unburned and partially burned propellant grains embedded in the skin around an entry wound. Cannot be wiped off. Pathognomonic for the int...
- Powder Tattooing, Stippling, Blackening and the Modified Griess TestIntradermal haemorrhagic punctate marks caused by wholly unburned propellant grains impacting and abrasion the superficial dermal layers at intermediate range....