Criminal tattoo

Criminal tattoos are a type of tattoos associated with criminals to show gang membership and record the wearer's personal history—such as their skills, specialties, accomplishments, incarceration, world view and/or means of personal expression. Tattoos are strongly empirically associated with deviance, personality disorders, and criminality.

Certain tattoo designs have developed recognized coded meanings. The code systems can be quite complex and because of the nature of what they encode, the designs of criminal tattoos are not widely recognized as such to outsiders.

Since tattooing in prison is illegal in the United States, the inmates do not have the proper equipment necessary for the practice. This forces inmates to find ways to create their own tattooing devices out of their belongings. Improvised tattooing equipment has been assembled from materials such as mechanical pencils, magnets, radio transistors, staples, paper clips or guitar strings.

N. Banerjee wrote in 1992 for the Wall Street Journal about tattoos in Russian prisons:

Russian criminal tattoos have a complex system of symbols which can give quite detailed information about the wearer. Not only do the symbols carry meaning but the area of the body on which they are placed may be meaningful too. The initiation tattoo of a new gang member is usually placed on the chest and may incorporate a rose. A rose on the chest is also used within the Russian Mafia. Wearing false or unearned tattoos is punishable in the criminal underworld, usually by removal of the tattoo, followed by beatings and sometimes rape, or even murder. Tattoos can be removed (voluntarily, in the case of loss of rank, new affiliation, "life style" change, etc.) by bandaging magnesium powder onto the surface of the skin, which dissolves the skin bearing the marks with painful caustic burns. This powder is gained by filing "light alloy" e.g. lawnmower casing, and is a jailhouse commodity.

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Wikipedia