Hearing aid battery used for prison tattoo

With reports of 3% of the prison population getting one or more illicit tattoos while incarcerated, the Canberra doctors are advocating regulated tattooing in prison to reduce the risks of bacterial and viral infection. 

To illustrate the point, they describe the discovery of a 42-year-old man who was using his hearing aid batteries to power a tattooing device. 

While the health risks around illicit tattooing are known, there is little to no discussion around the power source for the gun, the