Using the Physical and Chemical Characterization for the Ink of Laser Printer and Ballpoint Pen in Determination the Sequence of Their Intersection

Abstract

In the forensic document examination, the determination of the chronological order of intersection strokes of the toner and ballpoint inks is a paramount challenge issue. Two types of intersection are prepared on three different types of paper. A digital microscope and Raman spectroscopy are two nondestructive techniques used to determine these sequences via cross lines. Four physical characteristics observed at intersection point under the digital microscope were a specular reflection, the ink gloss, the ink spreading and gap. The results of the digital microscope determined the two types of intersections strokes except the red color of ink over toner. The results of Raman spectroscopy showed that the spectrum results at the intersection point similar to the pure ink executed later. The complementary technique of Raman spectroscopy and the digital microscope were necessary to achieve a complete determination of the sequences intersection strokes of the toner and ballpoint ink.