Ink Comparison and Interpretation

Abstract

This article focuses on the interpretation of the outcome of forensic ink analysis. Forensic analysis of ink can provide valuable information to forensic investigation of questioned documents. Ink analysis can be interpreted in a comparison process or in an identification process. This article formalizes these two processes and discusses the current limitations of the interpretation of ink analysis.

Emerging Approaches in the Analysis of Inks on Questioned Documents

“…While identification of the source of an ink entry would be particularly useful in questioned documents, it is generally only possible to determine the type of ink and its main components depending on the selected examination techniques [8]. Thus, it is possible with a low magnification microscope to determine that a ballpoint pen was used to draw an ink line, while chromatographic methods will help determine that the dye basic violet and the solvent phenoxethanol were contained in the questioned ink.…”

“…The diversity of compounds used in each categories of ingredients, combined with production impurities, is particularly interesting in a forensic identification perspective [8]. In practice, ballpoint pen inks (developed in 1930s [2]) are still the most commonly encountered in caseworks, together with inkjet and toner printers.…”

“…DSA uses a ion gun that direct heated nitrogen gas molecules at the samples in a mesh holder 8. DART uses stream of excited helium or nitrogen to ionize samples directly on the paper substrate.…”