1. A forensic system configured to acquire digital information recorded in a plurality of computers or a server, to analyze the acquired digital information, the system comprising: a digital information acquiring unit configured to acquire digital information including digital document information having a plurality of document files and user information related to a user who uses the plurality of computers or the server; a recording unit configured to record the digital information acquired by the digital information acquiring unit; a display unit configured to display the recorded digital information and the user information; a designation accepting unit configured to accept designation of at least one document file included in the digital document information, and to accept designation of a specific language into which the at least one document file, the designation of which is accepted, is translated; a translation processing unit configured to translate the at least one document file, the designation of which is accepted, into the language the designation of which is accepted; a common document file extracting unit configured to extract a common document file representing the same content as that of the designated document file from the digital document information recorded in the recording unit; a translation-related information generating unit configured to generate translation-related information representing that the extracted common document file is translated by invoking a translated content of the translated document file; and an output unit configured to output a litigant document file based on the translation-related information.