A method of getting a suspect to recall information about a case. According to the query personal library shows that the big memory recovery technique refers to the 1980s and 1990s in the last century, the sky network system (surveillance) is not yet developed, the investigation of the case to collect evidence is more difficult period, the police through a variety of interrogation techniques, so that the suspect a little bit of recall the scene of the crime of the various traces of the clues, so as to form a complete chain of evidence of the process.