The core function of Handwriting Examination is to determine whether samples of handwriting originate from one and the same writer.
In addition, a handwriting examiner may express opinions on the motor state of the writer. These statements will refer only to the way the shape of the handwriting sample is produced by the writer's movement. For instance, the motor state of the writer may be 'tremor' (for example due to Parkinsonism, substance abuse, emotion). The effects of the tremor may be visible in the handwritten trace. In such a case, it would be justifiable to mention the presence of 'tremor', but not its cause.
In addition to formulating conclusions regarding the origin of the handwriting, a handwriting examiner may also formulate a conclusion on the process of production (for example whether a signature is the product of a copying process). Although irregularities in the writing trace and pen pressure transitions may clearly indicate -i.e. constitute visible evidence of- for instance, interruptions in the writing process, it falls outside the scope of the handwriting examiner to make statements about the writer’s mental or physical state or personality traits.
Field of law: criminal law.
Boundaries of the field of expertise
Described below are those tasks in which a handwriting examiner does not engage and which are excluded from the field of Handwriting Examination.
A handwriting examiner will make no further inferences or answer any questions as to the writer of a sample that is being analysed other than those mentioned above.
A handwriting examiner will only express opinions based on handwriting samples written in a script type which falls within his expertise. For most European handwriting examiners, this will be Latin script (as opposed to for example Cyrillic or Arabic script). An exception may be made for signatures. Signatures can be legible (text-based) or illegible (stylized). Signatures in a script unfamiliar to the examiner can to some extent be processed like illegible signatures. The opinions of a handwriting examiner always have to be corroborated by reference to observable features in the writing trace.
A handwriting examiner must have sufficient knowledge to be able to decide whether the services of a document examiner are required.
The following activities emphatically do not belong to the field of expertise of handwriting examiners:
- Formulating conclusions on any personality traits of the writer on the basis of his handwriting.
- Formulating conclusions on the general or incidental mental or physical state of the writer on the basis of his handwriting.
- Formulating conclusions on the basis of the linguistic features of a handwritten text. However, a handwriting examiner may describe spelling features and punctuation typicalities.
- Formulating conclusions on samples collected from PCs. These require a specific expertise with a demonstrable experience.