Handwriting appraisal shall be conducted by an authoritative professional appraisal institution designated by the court. Handwriting identification is a special technique to identify the writer according to the characteristics of people's writing skills and habits and the reflection in writing handwriting and painting. The main task is to prove whether the handwriting on the documentary evidence is the same person's handwriting and whether the handwriting on the documentary evidence is the suspect's handwriting through the same handwriting identification test. Handwriting identification can test not only normal handwriting, but also handwriting with changing writing conditions (including writing posture, writing tools, filling, etc.). ), deliberately camouflage handwriting (including left-handed handwriting, ruler-drawn handwriting), imitate handwriting, and draw handwriting. When the same person writes with the same pen, the characteristics of pen marks can also be used to enrich the basis for identifying the writer.

Second, the requirements for applying for bill appraisal

Submitting judicial expertise is mainly in written form. A detained criminal suspect may orally apply for identification, but judicial personnel shall truthfully record it. The application for judicial authentication shall specify the cause of action, the object of authentication, the reasons for authentication, the authentication requirements and the judicial authentication institution or appraiser to be hired.

When a party applies for judicial expertise, it shall apply within the time limit of proof. If the party who bears the burden of proof fails to apply for appraisal within the time limit specified by the people's court without justifiable reasons, or fails to pay the appraisal fee in advance, or refuses to provide relevant materials for appraisal, so that the disputed facts in the case cannot be identified through appraisal, it shall bear the legal consequences of failing to prove the facts.