The purposes of this research were to study personal factors affecting credibility with the forensic examination report in the documentary fraud case of the inquiry officer. and study the level of credibility attitudes toward the forensic examination report in fraud cases, the documentary evidence of the inquiry officer, the sample group consisted of 400 lawyers in Khon Kaen, Udonthani, Nong Bua Lamphu and 5 in-depth interviews. The statistics were frequency, percentage, arithmetic mean, standard deviation, dependent samples t-test, and One Way Analysis, which tested statistically significant differences at the level of 0.05 and analyzed by using statistical software. The results: The most were 21-30 years men, finished Bachelor degree education, Buddhist marriage status, a lawyer Is the main occupation, the average monthly income of 17,424 baht and the validity of the license is 5 years, with opinions on the use of forensic documents. Report format Forensic examination of documents and reliability of the forensic documentary verification report in criminal cases, property fraud at a high level, and the highest level of education, religion and the average income per month are the trustworthiness of lawyers to the forensic examination report in criminal cases, property fraud, documentary witnesses of different investigating officers. The problems of the investigation report of the criminal investigation of the property of the investigating officer was unable to verify that the procedure before the report was written. The evidence was collected from the crime scene according to the law or not. Encourage lawyers to recognize the use of forensic documents in criminal cases, property fraud and pay attention to the credibility of the forensic examination report in criminal cases and property fraud.