Käsialatunnistus

Käsialatunnistus is the process of identifying or verifying the identity of an individual based on their handwriting. This is a specialized field within forensic science and document examination. Handwriting is considered unique to each person due to a combination of factors including motor skills, muscle memory, and learned writing habits. While no two people write exactly alike, the uniqueness of handwriting is not absolute, and there can be similarities.

The analysis involves comparing a questioned document (the handwriting in question) with known exemplar documents (handwriting from a known individual). Forensic document examiners look for a range of characteristics, known as "individualizing characteristics," which are minute and distinctive features of a person's writing. These can include variations in letter formation, slant, spacing, pressure, the way letters connect, and the presence of unique embellishments or errors.

Factors that can affect handwriting and pose challenges to identification include illness, injury, age, stress, the writing instrument used, the writing surface, and the speed of writing. Disguising handwriting is also a possibility, but it is difficult to consistently maintain a disguise while writing and avoid leaving behind natural characteristics.

Käsialatunnistus is used in various legal contexts, such as authenticating signatures on contracts, wills, and other legal documents, as well as in criminal investigations involving forged documents or ransom notes. The reliability of handwriting analysis is a subject of ongoing discussion and research within the scientific community.