About deleting file

myversa

This is from Mingpao's articles about Edison's case.  I am just wondering what is the 黑皮篋盛載先進的調查儀器 that can detect if the person has erased any computer files?  I thought if we do a low format and reinstall, everything will be wiped out?

昨午4時，探員掩至中環士丹利街50號eLite multimedia電腦店，要求負責人以鑰匙開閘，多名探員即急不及待打開店內多台電腦搜查。其間，探員又用一個紙箱及一個黑皮篋盛載先進的調查儀器入內，檢驗是否有人曾經刪除極重要的電腦檔案。經過近4小時搜查，探員將兩台桌面電腦主機及兩台手提電腦帶走檢驗。