article_snippet.sent: Investigators have been scouring Lubitz's computers to determine Lubitz state of mind before the tragedy .
article_snippet.sent: Once Captain Patrick Sodenheimer closed the cockpit door, Lubitz enabled special security features preventing the reinforced door from reopening.
article_snippet.sent: Already The safety systems has emerged that Lubitz used a rogue pilot computer to research methods of killing a rogue pilot as well as information concerning the cockpit door locking mechanism.
highlights_snippet.sent: Investigators have been searching Andreas Lubtiz's internet search history .
  
highlights_snippet.sent: Lubitz sought information online on various methods of taking Lubitz own life .
  
highlights_snippet.sent: Lubitz is also believed to have researched the cockpit door locking system .
  
highlights_snippet.sent: Investigators now want to determine why Lubitz left the cockpit door locking system .