Publication Year


Forensic Document Examination

From: Lawyer's Guide to the Forensic Sciences


Discusses forensic document examination, explaining the science of forensic document examination and its usefulness with handwriting comparisons. The chapter also describes the role of the forensic document examiner in criminal cases, and provides legal context.



Dan C Purdy

Dan C. Purdy, BSc, FSSocDip, FCSFS, D-ABFDE, majored in mathematics and physics at the University of British Columbia and, in 1969, joined the RCMP, completing a two-year training program in forensic document examination. Mr. Purdy joined the Canadian Society of Forensic Science in 1971 and served terms as a chairperson, director, and society treasurer. He transferred to the RCMP’s Ottawa laboratory in 1979 where he became head of the RCMP’s Document Operational Support Unit and Ottawa Document Section. He received a certificate of qualification in forensic document examination from the American Board of Forensic Document Examiners in 1980 and served as its president from 1993 to 1995. In 1989, Mr. Purdy was appointed the RCMP’s chief scientist of Document Services. In 1999, Mr. Purdy commenced work in the private sector. He is a member of the American Society of Questioned Document Examiners (serving as president from 2004 to 2006), the American Academy of Forensic Science, and a fellow of both the Chartered Society of Forensic Science and the CSFS. In 2012, Mr. Purdy was presented with the Albert S. Osborn Award of Excellence by the American Society of Questioned Document Examiners. Mr. Purdy has written over thirty scientific papers; examined over 4,500 cases; and testified as an expert witness in British Columbia, Alberta, Manitoba, Ontario, Quebec, Newfoundland & Labrador, the Yukon Territory, Nunavut, Bermuda, the United States, and Hong Kong. In 2015, he received the American Academy of Forensic Science’s Award of Merit.

Caitlin Pakosh

Caitlin M. Pakosh, HBSc, JD, has been working as case management counsel of Innocence Canada (formerly known as AIDWYC) since 2012 and is responsible for managing the Association’s cases across Canada. She obtained her honours bachelor of science degree, specializing in forensic anthropology and earning a minor in biology, from the University of Toronto Mississauga in 2008. Her undergraduate thesis, which examined the decomposition of dismembered pig limbs enclosed in plastic bags and submerged in Lake Ontario, was conducted during her internship with the Toronto Police Service Marine Unit and published in the Journal of Forensic Sciences in 2009. Ms. Pakosh obtained her Juris Doctor degree from the University of Calgary in 2011. She has appeared in the Court of Appeal for Ontario and has worked on intervener and appellate cases that have appeared at a variety of levels of court, including the Supreme Court of Canada, as well as ministerial review applications. Since 2013, Ms. Pakosh has cross-examined forensic science students in annual mock trials at the University of Toronto Mississauga, where students practise being expert witnesses. She is a member of the Criminal Lawyers’ Association and the National Association of Criminal Defense Lawyers. She is also an associate member of the American Academy of Forensic Sciences and the Canadian Society of Forensic Science.