Initial investigation was just interrogation with various people. It was not that authentic to build a case. UP police immaturely told a story which caught fire in the media and people started believing that story. The UP police could not have withstood this case in the court even for a single day. You should have evidence to back your case. CBI has all scientific evidence to back their case. On seeing those evidences the court has granted for talwars release. once scientifically proved, educates like you should try to accept and understand.