Lesson 3 - Forensics Writing Analysis


Lesson Objective: The student will ...

  • describe some forensic writing analysis techniques used to identify unknown documents, such as handwriting analysis, chromatography, and suspect document profiling 
  • analyze a criminal case that involves forensic writing analysis

Below is one of the most famous criminal documents of all time.  This letter was believed to be sent by the serial killer Jack the Ripper in October 1888.  Included with the letter was half a human kidney.  Examination of the kidney found it to be similar to one removed from a victim, but this finding was never confirmed.


Image courtesy of Stephen Ryder, 2006. (www.casebook.org/ ripper_letters/)
Click the image to enlarge it

Forensic Writing Analysis

The technique of forensic writing analysis is used by law enforcement in two ways:

  1. To determine if a document has been deliberately forged (cheques, written confession, suicide notes, lottery tickets)
  2. To determine the culprit responsible for writing a crime scene document ( ransom letter, threatening letter)

Interestingly, forensic writing analysis may involve not only documents written on paper. It may also involve writing found upon walls, windows, doors, or other crime scene objects. Forensic document analysis is a broad field that involves such scientific techniques as

  • handwriting analysis (graphology)
  • typescript analysis
  • paper analysis
  • chromatographic ink analysis
  • statement analysis profiling. 

This lesson will focuses upon graphology, chromatographic ink analysis, and statement analysis profiling.

Graphology

Graphology is based on the premise that each person has a unique handwriting style and many features make handwriting distinct.  Years of training and practical experience are necessary to be considered truly an expert in this field.  Three features of handwriting that are initially obvious include acquisition of slope, size of text, and design of letters and numbers.

  1. Acquisition of Slope  
  • The slope or angle of handwritten text is distinct and fixed, especially on unlined paper.
  • Many people write at a consistent angle on unlined paper; some others have difficulty writing at a consistent angle on unlined paper. 
  • If the slope changes, the writer likely did so deliberately. Often, writing samples from a suspect for comparison purposes is done upon unlined paper.
  1. Size of Text
  • In general, the size of handwritten text (letters and/or numbers) remains constant.  Some people write large text; others write small text.  The overall size of one’s writing is an important handwriting feature to note.  
  • People with good pen control tend to show strong consistency in letter size. Those with a lack of pen control show more variation in the size of their letters and words. 
  • The letters created in deliberately disguised writing tend to be larger than normal.
  1. Design of Lettes and Numbers 
  • Greater variation occurs in the design of more complex letters and numbers such as q, j, g, y, e, m, s, and 2, 4, 5, 8.  Notice that several of these complex letters have ‘tails’, a feature which varies significantly from person to person.
  • Less variation is evident in simple letters and numbers such as o, c, u, t, v, l,  and 0, 1, 6, 7, 9. 
  • Capital letters at the beginning of a sentence tend to be unique.

Graphology Example

Two writing samples from Individual A and Individual B.

Noticeable features:

  1. Acquisition of slope
  • Sentences of Individual A tend to slope downwards while Individual B’s sentences slope upwards.
  1. Letter size
  • Individual A’s letters are larger than Individual B's.
  1. Letter design
  • Individual A: Tail with loop on letters g and y (written or printed. Same written or printed letter s.
  • Individual B: Long and curled up tails on letters g and j (printed version). All written letters with tails have loops.
When young children first learn how to write, differences in their writing styles are less noticeable because they tend to consciously make identical copies of individual letters. As a child’s writing skills improve, the nerve impulses and motor movements become subconscious and the size, shape, and pattern of their letters take on a distinct style.

Did you know?

“The handwriting on the wall may be a forgery.”

- Ralph Hodgson

Continue to learn more about document analysis...