Forensic Analysis of Fountain Pen Calligraphy‐I. A Model Study

ABSTRACT The present study demonstrates that the X‐ray fluorescence (XRF) analysis of written characters on a sheet of paper (a model calligraphy) can identify the fountain pen. That is to say, the XRF analysis has the potential to prove the innocence of a person who served 31 years in prison (Sayama Incidence). He had maintained his innocence until his death. The XRF spectra in the present report were submitted to court before his death. A fountain pen was found in his house, and the pen was the evidence of murder committed by him. This is because the victim had the same kind of fountain pen. She wrote a calligraphy in a high school class and submitted it to the teacher, but she went missing late afternoon of that very day. The evidence has been kept in the Public Prosecutors Office. The defense attorney team has been permitted to examine the evidence, but the forensic analysis should be inside the Prosecutors Office. A handheld X‐ray fluorescence (HH‐XRF) spectrometer is selected. The calligraphy on a paper is mostly transparent for X‐rays, and several blank tests, as well as the backing of the calligraphy, are important in the present analysis. The calligraphy was sealed in a plastic bag when the XRF spectra were measured from outside of the plastic bag. The HH‐XRF can accomplish the necessary analyses non‐destructively within 1h including a control and several blank samples with a sufficient sensitivity of detection and sufficient accuracy of the quantification.