CFS - Technical Information Sheets - Handwriting
Technical Information Sheets
Forensic handwriting examination involves the examination and comparison of handwriting and signatures and often includes magnification with a hand lens and/or stereomicroscope.
Principle of Handwriting Identification
Two writings are the product of one person if the similarities, taken in combination, are sufficiently individual and there are no fundamental differences. The identification of signatures constitutes a special branch of handwriting identification in which letter design is considered in conjunction with the factors related to the execution of the signature. It is the combination of writing quality and form that identifies a signature.
Handwriting examinations include the following steps:
- The questioned and known items are examined to determine/assess their suitability for comparison (i.e. physical condition, comparable letter forms)
- Assessment of the naturalness or distorted appearance of the questioned and/or known writing
- A side-by-side comparison of known and questioned writings is conducted, noting any similarities and differences in characteristics
- A conclusion is reached based on an assessment of the significance of similarities and differences
- Individuality of the writing
- Quantity of comparable writing
- Quality/condition of the items on submission (i.e. non-original documents, fingerprinted documents)
- Conditions under which the writing was executed
Significance of Conclusions
- Definitive findings can be made in handwriting examinations provided sufficient, comparable questioned material and known samples are available
- It is often possible to determine whether a signature is a simulation but usually not possible to determine who simulated it
Range of Conclusions
The range of conclusions expressed by the Document Section at the Centre of Forensic Sciences is normally:
- Identification or Elimination
- Probable Identification or Elimination
- Unable to Determine/ Unable to Identify or Eliminate
Meanings of Conclusions
An identification means the combination of similarities points strongly towards two or more handwritten items having been written by the same person. There are no fundamental differences to suggest another writer. Identifications are made within the limits of practical certainty1,
1practical certainty - Since it is not possible to collect and examine samples of everyone’s handwriting it is not possible to make an identification with absolute certainty. However, all scientific research to date and the continuous inability to disprove the principle that no two people share the same combination of handwriting habits have demonstrated that even without a numerical threshold, handwriting examiners can reliably make identifications.
This is a qualified conclusion in which the combination of similarities points strongly towards two or more handwritten items having been written by the same person. There are no fundamental differences to suggest another writer; however, there were limitation(s) in the examination.
Elimination means that a known writer did not write the questioned writing.
This is a qualified conclusion in which comparison of the questioned to the known writings revealed some differences. These differences may not be fundamental, but they do point strongly toward two or more handwritten items having been written by different persons. This conclusion means the Forensic Document Examiner cannot preclude the slight or theoretical possibility that the two items were written by the same person.
Unable to determine:
An “unable to determine” or “unable to identify or eliminate” conclusion means it cannot be concluded whether or not the known writer wrote the questioned items.
characteristics / features
- properties of handwriting, such as: letterform/design, relative sizes and heights of letters, line quality, slope, arrangement, spacing, writing style, and skill level
- a characteristic/feature not in common between the questioned and known writing
- the writing of an individual who is deliberately altering the appearance of the writing by altering their usual writing habits in an attempt to conceal identity
- that quality of writing which reflects freedom of movement
- a difference in some natural feature that is indicative of a person’s writing habit and whose presence cannot be reasonably explained
- a repeated element or detail that may serve to individualize writing
- a characteristic or a combination of characteristics that distinguish(es) one person or thing from another
- the appearance of the written stroke caused by the basic movements and the manner of manipulating the writing instrument
- results from the combination of such factors as skill of the writer, writing fluency, fluctuations in pen pressure and smoothness of movement which are manifested by the presence/absence of features such as pen-lifts, hesitations, tremor, blunt or tapered beginning and/or ending strokes, abrupt directional changes, starts and stops
- variation in handwriting features found between repeated specimens of an individual’s natural handwriting
- a feature that is sufficiently individual to serve as a fundamental point of identification
- a characteristic/feature in common between the questioned and known writing
- a signature that was executed either by free-hand copying with or without the aid of a genuine model signature or by directly tracing the outline of a genuine signature