what is paraffin test

A paraffin test, also known as the dermal nitrate or diphenylamine test, is an early method used for detection of gunshot residue. It involves taking a cast of a suspects hand using hot paraffin wax, which is then sprayed with a reagent to gauge the presence of propellant particles. This test is no longer used in casework, as it has been replaced by more reliable chemical tests such as the Modified Griess test and the sodium rhodizonate test.