Model for electrostatic imaging of forensic evidence via discharge through Mylar-paper path

A model for the electrostatic detection apparatus is presented. An electrostatic potential models the effects of indented writing, erasures, and fingerprints. Poole–Frenkel emission from Mylar surface states is employed to model the discharge process. Experimental evidence is provided which supports the model. The role of the Mylar sheet is identified. The electric effect of indented writing is identified as a surface charge created by paper-to-paper friction.