Handwriting identification can last for up to five years. The time of handwriting formation can be identified from the following aspects: 1. By identifying the ink components of different handwriting, it can be judged whether it was written by the same pen or by the same person at one time; 2. If the handwriting overlaps or overlaps with the seal or fingerprint, it can be seen from the instrument, equipment and microscope whether it is printed first or written first, which can be used for Zhu Mo time series identification; 3. According to the specific situation of the materials provided, we can determine the formation order of different parts of the document. Some signed their names on the white paper first, and then added some contents.

General rules of judicial expertise procedure

Article 90

In order to find out the case, it is necessary to solve the controversial special problems in the case, and personnel with specialized knowledge shall be appointed or hired for identification; After the appraisal, the appraiser shall write an appraisal opinion and sign it. Article 33

In the process of identification, if complex, difficult and special technical problems are involved, experts in related professional fields outside the institution may be consulted, but the final expert opinion shall be issued by the judicial appraiser of the institution.

Expert opinions shall be signed and stored in the appraisal file.