Famous Cases Of Handwriting Analysis In Criminal Investigations

Handwriting analysis, also known as graphology, is the study and analysis of an individual’s handwriting to determine personality traits and characteristics. It has been used as a forensic tool in criminal investigations for over a century. According to the History of Handwriting Analysis, the first recorded handwriting analysis case dates back to 1877 in France, where a man’s will was determined to be a forgery based on handwriting analysis. Since then, the technique has been used in high-profile criminal cases to compare handwritten notes, letters, and documents to aid in identifying criminals.

Handwriting analysis is based on the theory that handwriting is brain writing, meaning it originates in the brain and reflects a person’s psychological makeup. Factors like pen pressure, slant, size, spacing, and curvature reveal information about personality, emotional state, and patterns of thinking. In criminal investigations, handwriting analysis may help determine if a suspect authored a handwritten note such as a ransom note, suicide note or threat letter. It can also aid in verifying or determining the validity of documents such as wills, contracts, and diaries. While results of handwriting analysis alone are not conclusive evidence, when combined with other forensic evidence, it can provide investigators valuable insights.

Lindbergh Kidnapping Case

In 1932, Charles Lindbergh Jr., the 20-month-old son of aviator Charles Lindbergh, was kidnapped from his family’s home in New Jersey. Ransom notes were delivered, demanding money in exchange for the return of the child. Tragically, the child’s body was discovered a few months later. A key piece of evidence was analysis of the handwriting from the ransom notes, which matched the writing of Bruno Richard Hauptmann, a German immigrant. Handwriting experts compared Hauptmann’s writing samples to the ransom notes and found distinct similarities in letter formations and writing style. In multiple court testimonies, examiners methodically pointed out the matching slants of letters, letter connections, and shapes of letters between Hauptmann’s handwriting exemplars and the ransom notes. This handwriting analysis provided damning evidence that led to Hauptmann’s conviction and execution in 1936.

Zodiac Killer

The Zodiac Killer was an unidentified serial killer who terrorized Northern California in the late 1960s and early 1970s. Though the killer’s identity remains unknown, investigators were able to obtain several handwritten letters and cryptograms sent by the Zodiac to newspapers and police. Handwriting analysis has been extensively used in attempts to uncover the identity of the Zodiac Killer, though without definitive success.

According to handwriting expert Nanette Barto, some key findings from analysis of the Zodiac’s letters include that he was right-handed, very controlled and organized, and sought attention and notoriety for his crimes [1]. His writing showed signs of high intelligence but also mental illness. Though handwriting comparisons to suspects like Arthur Leigh Allen have proven inconclusive, the analysis has provided insight into the killer’s personality and motives.

While handwriting analysis has not led directly to the capture of the Zodiac Killer, it remains one investigative technique among many that may someday help unlock this infamous cold case. The availability of the Zodiac’s extensive written communications provides an intriguing opportunity for experts to glean information about the author.

Green River Killer

The Green River Killer, Gary Ridgway, was arrested and charged with 48 counts of aggravated first degree murder in November 2001. He confessed to killing at least 71 women over the course of two decades. Ridgway targeted prostitutes and runaways in the Seattle-Tacoma area and disposed of their bodies along the Green River, giving rise to his infamous moniker.

In the 1980s, investigators received a series of letters from someone claiming to be the Green River Killer. The letters contained details about the murders that had not been released to the public, leading authorities to believe they were authentic. The letters were turned over to forensic document examiners for handwriting analysis. The examiners concluded the handwriting matched samples obtained from Ridgway, who had become a suspect early on in the investigation. This handwriting evidence was critical in tying Ridgway to the Green River killings.

According to expert graphologist Pennie Morehead, Ridgway’s handwriting indicated narcissistic and psychopathic tendencies. His uneven letter slants and variations in pressure pointed to his erratic, impulsive personality. Morehead noted that Ridgway’s writing sloped downward, suggesting deep-seated anger and hostility toward women. The extreme variations between thick and thin strokes reflected the dichotomy between his charming public persona and violent private self. While handwriting analysis alone did not lead to Ridgway’s arrest and conviction, it provided one more critical piece of evidence out of the killer’s own hand.

[1] [https://www.crimelibrary.org/serial_killers/predators/greenriver/9.html]

BTK Killer

Dennis Rader, better known as the BTK (“Bind, Torture, Kill”) Killer terrorized the Wichita, KS area for nearly two decades. He tortured 10 known victims prior to killing them between 1974 and 1991.

In 1978 BTK sent a package to law enforcement that confessed to the murder of seven individuals, a sketch, and a poem. At this time Rader was trying to get more attention from the media.

After a long hiatus, Rader resumed communication with authorities and media in 2004, leading ultimately to his arrest, trial and conviction in 2005. Handwriting analysis and comparison of documents played a key role. Investigators found similarities between the 1978 communications and the 2004 letters, identifying Dennis Rader as the author of both through handwriting analysis. This evidence was critical in linking Rader to the BTK murders and securing his conviction (Source).

Son of Sam

David Berkowitz, also known as the Son of Sam, carried out a series of shootings in New York City between 1976-1977. He killed 6 people and wounded 7 others in 8 separate attacks. Berkowitz sent taunting letters to police and the press, referring to himself as the Son of Sam.

Handwriting analysis helped investigators link the letters to Berkowitz. NYPD lieutenant Joseph Borelli noticed similarities between the handwriting in the letters and a parking ticket that Berkowitz had received. This clue led to Berkowitz’s arrest in August 1977. After his arrest, he confessed to acting alone in the shootings.

Graphology experts have analyzed Berkowitz’s handwriting over the years. According to graphologist Michelle Dresbold, his handwriting showed indicators of schizoid personality disorder and paranoid schizophrenia. The dramatic variations between letters were indicative of multiple personality shifts. His handwriting also pointed to repressed rage, difficulty forming relationships, and isolation.

Berkowitz’s handwriting showed irregular slanting, poor word spacing, inconsistent letter formations, and heavy pen pressure. These characteristics provided insight into his troubled and deranged mindset. Ultimately, handwriting analysis was key to cracking the Son of Sam case through its identification of Berkowitz as the letter writer.


Theodore Kaczynski, also known as the Unabomber, was an American domestic terrorist known for sending mail bombs to various universities and airlines between the late 1970s and early 1990s. He ultimately killed 3 people and injured 23. His unique linguistic patterns and unusual content in his 35,000 word manifesto titled “Industrial Society and Its Future” ultimately led to his capture.

In 1995, the FBI enlisted forensic linguist James R. Fitzgerald to analyze the Unabomber’s writings after newspapers published the manifesto. Fitzgerald was able to connect patterns such as Kaczynski’s use of the phrase “cool-headed logicians” and unique spellings like “clew” instead of “clue” to letters from Kaczynski that the FBI had on file. This forensic linguistics breakthrough directed the FBI’s investigation towards Kaczynski (https://theconversation.com/how-the-unabombers-unique-linguistic-fingerprints-led-to-his-capture-207681).

The FBI arrested Kaczynski in 1996. He pleaded guilty in 1998 and is currently serving a life sentence without the possibility of parole.

Handwriting Analysis Methods

Handwriting analysis, also known as graphology, involves examining the characteristics of a person’s handwriting to gain insight into their personality and other attributes. Some key techniques used in handwriting analysis include:

Graphology – The study of handwriting strokes and patterns to assess personality traits. Graphologists analyze things like slant, pressure, spacing, and size of handwriting features.

Stroke Patterns – The direction, flow, ends, and beginnings of writing strokes are examined. The thinking is strokes reflect the writer’s emotion and movement.

Slant – The direction of slanting letters is interpreted. For example, right slant may indicate responsiveness, left slant introspection.

Letter Spacing – The amount of space between letters supposedly reveals traits like caution, reserve, vigilance, and enthusiasm. Tight spacing could mean constriction.

Size – Smaller writing is thought to indicate humility and larger writing may reflect an outgoing nature.

Pressure​ – Heavy pressure indicates commitment or emotional intensity, light pressure is seen as sensitivity.

Signature – Signatures are especially revealing as they are meant to represent an individual’s public persona. Elaborate signatures may reflect vanity.

While popular, handwriting analysis is controversial as results can be subjective. Some techniques used include holographic analysis and computerized handwriting recognition (1).

Famous Handwriting Experts

Michelle Dresbold is one of the most well-known and respected handwriting experts working today. She has over 15 years of experience analyzing handwriting and signatures in criminal investigations and civil cases. Dresbold has worked on high-profile cases like the JonBenet Ramsey murder, the Columbine massacre, and the Black Dahlia case. She is considered a leading authority in handwriting identification and has testified in court over 300 times.

Dresbold is the author of several books on handwriting analysis, including ‘Sex, Lies, and Handwriting’ and ‘Handwriting of the Famous and Infamous’. She also runs a handwriting analysis firm where she provides services like personality profiles based on handwriting samples. Dresbold frequently appears on TV programs as an expert commentator on cases involving questioned documents and handwriting evidence. She aims to raise awareness of the validity and reliability of handwriting analysis as a forensic science.


Handwriting analysis has proven to be a valuable tool in criminal investigations over the years, helping investigators and prosecutors identify suspects and secure convictions in high-profile cases like the Lindbergh kidnapping and Son of Sam. As demonstrated through these cases, forensic handwriting experts can provide critical evidence by identifying handwriting characteristics and matching writing samples to suspects. While the future of handwriting analysis has come into question with the rise of digital communications, recent studies show that these experts can still play an important role, especially with the emergence of new technologies like computer-assisted handwriting analysis.1

Looking ahead, handwriting analysis will likely remain a useful technique for law enforcement, but may be applied more selectively in cases where handwriting evidence is abundant. Additional research will be needed to further establish the accuracy and reliability of handwriting analysis, but thus far it has proved valuable in catching criminals and exonerating innocent suspects. While handwriting may not provide definitive proof on its own, it can yield valuable clues and developments that aid investigators. By continuing research and improving methods like computer algorithms, forensic experts can work to make handwriting comparisons even more accurate and standardized.2 With science and technology progressing, handwriting analysis will likely continue evolving as an important tool for fighting crime in the digital age.

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