Understanding How Handwriting Analysis Works

When a handwritten note is involved in a crime investigation, experts in handwriting analysis may be brought in to determine if the writing matches a suspect's. In some cases, it can be the crucial piece of evidence that leads to an arrest and a conviction. But what happens if the match is incorrect? How do experts precisely analyze someone's handwriting?

Handwriting analysis is a part of forensic science, alongside other disciplines like crime scene investigation, DNA testing, fingerprint analysis, voice identification, and drug analysis. This field, known as questioned documents, examines characteristics like letter slants, rounded shapes, and more to identify if a document has been altered or forged.

Discover how a simple writing sample can uncover significant truths.

What Is Handwriting Analysis?

Questioned document examiners (QDEs) investigate documents for indications of forgery, alteration, and, when available, handwriting or typewritten samples to determine or exclude potential authorship (and/or link a document to a particular typewriter or machine in the case of typing).

Handwriting analysis is a detailed and systematic practice that requires a deep understanding of the unique ways people form letters, including variations in pressure, letter size, spacing, and more.

The distinctive features of how letters are formed are highly individual, and the physiological processes involved in writing — how one's fine motor skills influence their handwriting — can provide valuable clues about the writer's identity.

Foundations of Handwriting in Childhood

The core principle behind handwriting analysis as a science is that each individual has a distinctive way of writing. As children in elementary school, we all learned to write according to a particular copybook — a prescribed writing style. The copybook we learned from depended on the era and place where we grew up.

Initially, our handwriting likely resembled that of other children from our same age group and region. Over time, however, the style we were taught in school became the foundation for our handwriting, while we gradually developed unique characteristics that set our handwriting apart from others.

Most of us no longer write the way we did in early elementary grades. Although two or more people might share a few traits in their handwriting, the likelihood of them having 20 or 30 matching traits is so small that many handwriting experts would consider it impossible.

Style vs. Personal Handwriting Traits

First and foremost, handwriting experts need to distinguish accurately between style traits and personal traits, a skill that requires extensive training.

Style traits are generally disregarded, as they mainly serve to identify which copybook the writer used. The primary focus lies on individual characteristics, which are crucial for determining authorship.

When analyzing two documents — one from a known author and the other from an unknown source — the process doesn't begin by identifying similarities, which most people could do fairly easily. Instead, it starts with looking for differences. These differences help determine whether it's even plausible that the same person wrote both documents.

If there are significant differences in enough personal traits, and these differences don’t seem to result from an attempt to imitate or conceal handwriting, then it can be concluded that the documents were written by different people.

Simulation has its own recognizable traits. However, if the differences don’t rule out the possibility of a match and there are notable similarities in the personal characteristics between the two documents, it becomes conceivable that they were written by the same person.

The transition from possibility to probability is where the real work begins.

Richard Bruno Hauptmann's Handwriting Samples

Handwriting analysis is a meticulous process that requires time and, ideally, numerous comparison samples — known documents from a confirmed author. It's not as simple as noting, 'Hey, both documents feature a 'B' with a downstroke — same person!'

During the 1932 Lindbergh kidnapping case, the police collected several questioned documents — 14 ransom notes in total from the kidnapper. Handwriting experts had no difficulty confirming that all of the notes came from the same individual.

Exemplars from the primary suspect, Richard Bruno Hauptmann, were scarce, so the police resorted to obtaining samples from him at the station through dictation. From these samples, handwriting experts identified a match.

However, the methods used by the police to collect these samples have been heavily criticized — they made Hauptmann write for hours until he was near exhaustion. They also instructed him on how to write and showed him a ransom note, asking him to mimic the handwriting, among other significant violations.

This raises doubts about the reliability of the handwriting match, and since Hauptmann was executed, a re-evaluation is no longer possible. Strict regulations are now in place regarding how law enforcement should collect requested handwriting samples.

Analyzing a Writing Sample

Quality, uncontaminated, and abundant exemplars make handwriting analysis significantly more accurate than a simple one-to-one comparison. While each person's handwriting is unique, no individual writes in exactly the same way every time; natural variations occur within a single document.

For instance, if a suspect provides 10 writing samples and there are 10 questioned documents, it ensures that not only will the words and letters in the questioned documents appear in the samples, but almost all the individual characteristics of the suspect will be present in both sets if they are indeed the writer of both.

Professional forensic handwriting analysis demands meticulous attention to detail. Analysts may use magnifying glasses and sometimes even microscopes during comparisons. They focus on a variety of unique characteristics when reviewing writing samples:

Given these traits, a typical comparison method begins with the first letter of the first word in the questioned document, and the analyst proceeds to build a comparison table.

To demonstrate, we will conduct a simulated comparison between a questioned document and an exemplar, each consisting of a single sentence — a challenging task for determining a clear match or non-match in real cases, but ideal for our illustrative purposes.

At first glance, these two samples may not seem significantly different enough to immediately conclude that they were written by two distinct individuals. Upon further inspection, however, they do appear to share notable similarities. Therefore, we will create a table to catalog every unique form of each letter that appears in the questioned version of this sentence.

If we encounter an "a" that matches one already recorded in our table, we skip it. Our goal is to document every distinct variation of the letter "a" in the questioned document, taking into account factors such as letter formation, linking strokes, spacing, and other distinguishing features.

In professional forensics, they would typically capture each letter form using a digital camera, but for this example, we will manually document it. They would also create separate tables for uppercase and lowercase letters. However, we'll simplify the process for our illustration, as this is just a demonstration of how to determine a match or mismatch, rather than a precise, professional comparison.

Next, we will construct a similar table using the exemplar.

Finally, we will compare the two tables and check if each questioned document's letter form matches a corresponding one in the exemplar. Given that our document is just a single sentence, there aren't many examples to work with.

Under typical conditions, we would have a variety of potential matches for each letter form, and our goal would be to find the best match in the exemplar for each letter form present in the questioned document.

For simplicity's sake, our third table will feature a side-by-side comparison of the two initial tables, although a professional analyst would likely create a third table that specifically highlights the exact words from each document that correspond to each letter-form match.

While this analysis wouldn't stand up in court due to its limited scope and the inaccurate reproduction of letters, it does seem that we've found a match for every letter in the questioned document within the exemplar. It's likely that the same person wrote both sentences.

But what if the writer of the exemplar was attempting to replicate the handwriting in the questioned document? The issue of simulation presents a major challenge in handwriting analysis. Simulation happens when someone deliberately tries to either conceal their handwriting to prevent matching or imitate someone else's handwriting to encourage an inaccurate match.

While simulation complicates an accurate analysis (and in some cases makes it impossible), there are specific traits that forensic analysts look for to identify a simulated handwriting sample. These include inconsistent line quality, thick and dark word beginnings and endings, and numerous pen lifts, all indicative of slow, deliberate letter formation rather than quick, natural writing.

Simulation is just one of the many obstacles that can hinder the accuracy of a handwriting analysis.

The Limitations of Handwriting Analysis

Although skilled experts can often detect instances of forgery, some well-crafted imitations may evade detection altogether. A notable example is the case of the infamous "lost" Hitler diaries, which eluded the attention of experts for quite some time. (There are, however, valid reasons for this oversight.)

In the 1980s, a man by the name of Konrad Kujau, claiming to be a collector of Nazi memorabilia, approached a German publishing house with 60 handwritten diaries that he alleged had been penned by Adolf Hitler. According to Kujau, these journals had been recently uncovered in the wreckage of a plane that had left Germany after World War II. The texts appeared convincing, and Kujau seemed reputable, so the publishing company purchased them for $2.3 million.

First Verification

The company swiftly began publishing the diaries in serialized installments in a German newspaper owned by the same publishing house, also selling syndication rights to various international outlets, including The London Times. It was The Times that requested a professional handwriting analysis to authenticate the documents.

Three renowned international specialists in forensic handwriting analysis conducted a comparison of the diaries against known examples of Adolf Hitler's handwriting. All three experts reached the same conclusion: the same person who wrote the exemplars also wrote the diaries. The diaries were deemed authentic.

Differences in Material

It was through an analysis of the ink and paper used in the diaries that their true nature as forgeries was uncovered. A test with ultraviolet light revealed that the paper contained an ingredient that was not present in paper until 1954—nine years after Hitler's death in 1945.

Additional forensic tests on the ink confirmed that it had been applied to the paper in the past 12 months.

A Surprising Development

It turns out, however, that the handwriting analysis was correct all along—the individual who wrote the diaries was indeed the same person who had penned the exemplars. Kujau, who was later revealed to be a seasoned fraudster, had also forged the exemplars that the authorities had been using for comparison.

Key Takeaways

The scandal surrounding the Hitler diaries is an extreme example of fraud and expert-level forgery that affected every aspect of the analysis process. Although such high levels of deception are rare in forgeries, the fact remains that if the investigation had relied solely on handwriting analysis, the "lost Hitler diaries" might have been accepted as historical fact.

Other factors that can influence the accuracy of handwriting analysis include:

In the initial handwriting analysis of the case involving John Mark Karr, who confessed in August 2006 to the 1996 murder of six-year-old JonBenet Ramsey in Colorado, the ransom note discovered at the Ramsey residence was lengthy enough to serve as a key piece of evidence. However, finding suitable exemplars for comparison posed a challenge.

Document expert John Hargett, former head of document analysis at the U.S. Secret Service, conducted a series of preliminary analyses, comparing the ransom note to two available exemplars: a high school yearbook inscription written by Karr and a job application Karr filled out in Thailand.

Hargett found no matches, although the results were inconclusive. This was due to the fact that the yearbook inscription was written over 20 years ago and in an artistic style, while Karr had filled out the job application in Thailand entirely in uppercase letters, whereas the ransom note combined both uppercase and lowercase letters.

Later, DNA testing rendered further handwriting comparisons unnecessary, as Karr's DNA did not match the DNA found on JonBenet's body.

The Major Limitation

One of the main limitations of using handwriting analysis as a scientific method is its inherent subjectivity. As a result, it has faced challenges in gaining widespread acceptance within the scientific community and as admissible evidence in court cases over time.

Recently, however, as training for analysts has become more consistent and certification programs have been established, handwriting analysis is gradually gaining recognition as a reproducible, peer-reviewed scientific technique.

Despite this progress, handwriting comparison results are still not universally accepted in court as reliable evidence. This is partly due to unresolved challenges such as determining a dependable error rate for analysis and establishing consistent standards for the comparison process.

The introduction of computerized handwriting analysis systems, like FISH (Forensic Information System for Handwriting), which allows examiners to scan and digitize handwritten documents for comparison, may accelerate the acceptance of handwriting analysis as both a scientific method and a legitimate form of expert evidence in court.

Graphology

You may have come across the idea that writing in very small letters suggests you're subconsciously trying to conceal something, or that using much larger initial letters for your name indicates a desire for attention.

These kinds of interpretations, which claim to reveal traits like a tendency for rebellion or a preference for avoiding conflict based on your handwriting style, fall under the category of graphology, an art distinct from forensic handwriting analysis.

Forensic handwriting analysis, on the other hand, focuses on comparing multiple documents and determining, with a high degree of certainty, whether they were written by the same individual or by different people.