How Handwriting Analysis Works

Shortcomings of Handwriting Analysis

­While an expert analyst can detect many instances of forgery, a good simulation can be undete­ctable. One example of a forgery the experts missed is the case of the "lost" Hitler diaries. (Although there's a good reason why they missed it.)

In the 1980s, a man named Konrad Kujau, a supposed collector of Nazi memorabilia, approached a German publishing company with 60 handwritten journals purported to be written by Adolf Hitler that had, according to Kujau, just been discovered in the wreckage of an airplane that had left Germany after World War II. The texts seemed to be genuine, and Kujau had an apparently good reputation, so the publishing company paid $2.3 million for the lot. The diaries were immediately published in installment form in a German newspaper owned by the same publishing company, and syndication rights were sold to several international publications, including The London Times. It was The Times that requested a professional handwriting analysis to ensure authenticity.

Three international experts in forensic handwriting analysis compared the diaries to exemplars that were apparently known to be written by Hitler. All agreed that the diaries were written by the same person who wrote the exemplars. The diaries were for real.

It was an analysis of the ink and paper used to write the diaries that revealed them as fakes. An ultraviolet-light examination revealed that the paper contained an ingredient that wasn't used in paper until 1954. Hitler died in 1945. Further forensic tests on the ink showed it had been applied to the paper within the last 12 months. As it turns out, though, the handwriting analysis was in fact correct - the person who'd written the diaries had also written the exemplars. Kujau, later found out to be an experienced con artist, had also forged the exemplars the police were using as comparison documents.

The Hitler diaries debacle is an extreme case of fraud and expert forgery that spanned every stage of the analysis. And while this level of expertise is seldom found in forgeries, the fact remains that if the investigation had relied on handwriting analysis alone, the "lost Hitler diaries" would now be part of the history books. Some other issues affecting the accuracy of handwriting analysis include:

  • You can't make a meaningful comparison between uppercase and lowercase letters.
  • Drugs, exhaustion or illness can significantly alter a person's handwriting.
  • The quality of the exemplars determines the quality of a comparison analysis, and good exemplars can be hard to come by.

­In the initial comparison work done in the case of John Mark Karr, who confessed in August 2006 to the 1996 murder of six-year-old JonBenet Ramsey in Colorado, the ransom note found in the Ramsey house was long enough to be useful as one side of the equation, but finding good exemplars was an issue. In a series of preliminary handwriting analyses, documents expert John Hargett, former head of document analysis at the U.S. Secret Service, compared the ransom note to two exemplars: a yearbook inscription written when Karr was in high school and a job application Karr filled out in Thailand. Hargett found no matches, although the results were inconclusive because the yearbook inscription was written more than 20 years ago and in an artistic writing style, and Karr filled out the Thailand job application in all uppercase letters, while the ransom note was written in both uppercase and lowercase letters. DNA testing later made further handwriting comparisons unnecessary, as Karr's DNA was not a match for the DNA found on JonBenet's body.

Certainly the most significant shortcoming of handwriting analysis as a science is the fact that it is ultimately subjective. This means that its acceptance in the scientific community and as evidence in court has historically been shaky. Only recently, as the training of analysts has become more standardized and certification procedures have been put in place, has handwriting analysis started to gain more acceptance as a reproducible, peer-reviewed scientific process. The results of a handwriting comparison are still not always accepted as evidence in a court case, partly because the science has a few more hurdles to clear, including determining a reliable error rate in analysis and setting standards for the comparison process. The addition of computerized handwriting analysis systems to the process, including the FISH (Forensic Information System for Handwriting) system, which allows examiners to scan in handwritten documents and digitize the comparison process, may speed up the process of general acceptance of handwriting analysis as a science and as expert evidence in court.

For more information on handwriting analysis and related topics, check out the links below.

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More Great Links


  • Cohen, Fritz. "Scientific Handwriting Analysis." National Handwriting Association.
  • Found, B., & Rogers, D. "Documentation of Forensic Handwriting Comparison and Identification Method: A Modular Approach." Journal of Forensic Document Examination. 1999.
  • "Handwriting, Typewriting, Shoeprints, and Tire Treads: FBI Laboratory's Questioned Documents Unit."
  • "JonBenet suspect to return to U.S. on Sunday." Aug. 19, 2006.
  • "Is handwriting analysis legit science?" The Straight Dope.
  • "LIMA: Forensic Handwriting Analysis." Warwick Centre for the Study of the Rennaissance.
  • Ramsland, Katherine. "Literary Forensics." CourtTV Crime Library.
  • "The Thornton Handwriting Examination Court Decision."