Legal analysis: according to fingerprints. According to China's criminal procedure legal system, the confession of a witness or criminal suspect, if the parties can't write, can be signed by handprint, which has the same legal effect.

Legal basis: Article 122 of the Criminal Procedure Law of People's Republic of China (PRC) should be checked by the criminal suspect and read to him if he can't read. If there are omissions or errors in the record, the criminal suspect may make additions or corrections. The criminal suspect shall sign or seal his name after admitting that it is correct in the record. Investigators should also sign the records. If a criminal suspect requests to write his own confession, it shall be allowed. When necessary, investigators may also ask the criminal suspect to write a confession in person.