The process of criminal investigation based on grey hazy set

Based on the concept of grey hazy set in the grey system, this paper discusses the criminal investigation´ 4-IN property, and describes the process of the criminal investigation from a new point view in details, it concludes that the precess of criminal investigation is a sequential evolution process of four different forms (Embryo, Growing, Mature and Evident) in the grey hazy set. The conclusion benefits the application of the grey system theory to criminal investigation concerned with the analysis, modeling, prediction and decision making.