Skip to content

handwriter: a Demonstration and Update on CSAFE Handwriting Analysis

Published: 2022
Primary Author: Dr. Alicia Carriquiry
Secondary Authors: Dr. Stephanie Reinders
Type: Webinar

This CSAFE webinar was held on October 18, 2022.

Presenters:
Alicia Carriquiry
Director, CSAFE
Distinguished Professor and President’s Chair, Department of Statistics – Iowa State University

Stephanie Reinders
Research Scientist, CSAFE

Presentation Description:

Forensic handwriting analysis relies on the principle of individuality: no two writers produce identical writing, and given enough quality and quantity of writing, it is possible to infer whether two documents were written by the same person. Forensic handwriting analysis is carried out by examiners trained to find subtle differences and similarities between a questioned document and a reference sample. Examiners visually compare samples and offer an opinion regarding the source of the questioned document.

In the last 10-15 years, researchers have proposed algorithmic tools to complement examiners’ visual assessments. A well-known software system called FLASH ID (Sciometrics, LLC) first decomposes the image of a questioned sample into structures called graphemes and then characterizes them by their topology and shape. Given a closed set of reference samples, the software computes a score that quantifies the similarity between the questioned document and the references. FLASH ID has been extensively tested and has been shown to exhibit very good accuracy.

At CSAFE, we are working on semi-automated methods suitable for closed or for open sets of reference writers, and for the examination of samples at the level of words or at the level of graphical structures similar, but not identical to graphemes. In the webinar we will describe each of the different methods, and show initial but promising results. When the reference set of writers is closed we use a Bayesian approach that outputs a probability of writership for each writer in the set. Because the output is an estimated probability, the interpretation of results is straightforward. We are still developing and testing the word-based approach and the more algorithmic approach that can be used when the set of potential writers is open, but can show some initial results and our plans for future developments. We will demonstrate our software to implement these methods: handwriter. The program is not yet fully functional, but an early version is in the public domain and can be freely accessed at https://github.com/CSAFE-ISU/handwriter.

 

Webinar Recording:

 

Related Resources

Source Camera Identification with Multi-Camera Smartphones

Source Camera Identification with Multi-Camera Smartphones

An overview of source camera identification on multi-camera smartphones, and introduction to the new CSAFE multi-camera smartphone image database, and a summary of recent results on the iPhone 14 Pro’s.
An alternative statistical framework for measuring proficiency

An alternative statistical framework for measuring proficiency

Item Response Theory, a class of statistical methods used prominently in educational testing, can be used to measure LPE proficiency in annual tests or research studies, while simultaneously accounting for…
Examiner variability in pattern evidence: proficiency, inconclusive tendency, and reporting styles

Examiner variability in pattern evidence: proficiency, inconclusive tendency, and reporting styles

The current approach to characterizing uncertainty in pattern evidence disciplines has focused on error rate studies, which provide aggregated error rates over many examiners and pieces of evidence. However, decisions…
Statistical Interpretation and Reporting of Fingerprint Evidence: FRStat Introduction and Overview

Statistical Interpretation and Reporting of Fingerprint Evidence: FRStat Introduction and Overview

The FRStat is a tool designed to help quantify the strength of fingerprint evidence. Following lengthy development and validation with assistance from CSAFE and NIST, in 2017 the FRStat was…