The principle of proportion is a specific golden section,which is harmonious,artistic and scientific.It′s the civilization′s reflection in law.Because the use of it in investigation embodies the principle of fitness,the principle of necessity,the principle of suitability,the principle of economy and the principle of justice,it has been the king principle of investigation.It is the token and direction of criminal investigation that how to bring into play this principle′s functions of regulation,control and p...