Germanwings co-pilot Andreas Lubitz had researched suicide methods and the security of cockpit doors in the week before the crash, German prosecutors say.
Andreas Lubitz, 27, is suspected of deliberately crashing Germanwings flight 4U 9525 into the French Alps on March 24.
German prosecutors said internet searches were found on a tablet used by Andreas Lubitz.
Meanwhile, the second “black box” flight recorder from the plane has been recovered.
There were no survivors among the 150 people on board the Airbus A320.
The German prosecutors said internet searches made on the tablet found in Andreas Lubitz’s Duesseldorf flat included “ways to commit suicide” and “cockpit doors and their security provisions”.
Spokesman Ralf Herrenbrueck said: “He concerned himself on one hand with medical treatment methods, on the other hand with types and ways of going about a suicide.
“In addition, on at least one day he concerned himself with search terms about cockpit doors and their security precautions.”
Andreas Lubitz had been deemed fit to fly by his employers at Germanwings, a subsidiary of Lufthansa.
Based on voice recordings from the first flight recorder recovered almost immediately at the crash site, investigators believe Andreas Lubitz intentionally crashed Flight 9525, which was travelling from Barcelona to Duesseldorf.
The second “black box” recovered is the flight data recorder (FDR) with readings for nearly every instrument seen as vital to the investigation into the crash.
If the flight recorder is not too badly damaged, French investigators hope to retrieve technical information on the time of radio transmissions and the plane’s acceleration, airspeed, altitude and direction.
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