The prosecutor has confirmed the Co-pilot a German national deliberately crashed his plane into the Alps.
Once the pilot left the cockpit to use the toilet the co-pilot activated the descent button and refused to open the cockpit door to the pilot.
The pilot attempted in vain to force entry back into the cockpit, and attempted to bang on the door to re-gain entry.
The Co-Pilot has been named as Andreas Lubitz, 28 and he was alive until the final impact.
The Airbus 320 which was travelling from Barcelona to Duesseldorf hit a mountain killing all 144 passengers and six crew members.
The pilot attempted for eight-minutes to gain entry in to the cockpit. .