Investigation is a basic and separate phase in the criminal procedure of our country and it is also an essential procedure of public prosecution cases . not only does it provide the basis straight for the arrest authorized by investigating and prosecuting apparatus , but also determines courts " adjudgement to a great extent 侦查是我国刑事诉讼的一个基本、独立的诉讼阶段,是公诉案件的必经程序。它不仅直接为检察机关的批捕和起诉提供依据,同时还在很大程度上决定着法院审判的结果,是刑事司法活动的重要组成部分。