Germanwings crash: Prosecutors dig into co-pilot's background

This is an undated image taken from Facebook of Germanwings co-pilot Andreas Lubitz in San Francisco California. Lubitz the co-pilot of the Germanwings jet barricaded himself in the cockpit and 'intentionally' rammed the plane full speed into the French Alps on Tuesday, ignoring the captain�s frantic pounding on the cockpit door and the screams of terror from passengers, a prosecutor said Thursday March 26, 2015. In a split second, he killed all 150 people aboard the plane. (AP Photo) NO SALES

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This is an undated image taken from Facebook of Germanwings co-pilot Andreas Lubitz in San Francisco California. Lubitz the co-pilot of the Germanwings jet barricaded himself in the cockpit and 'intentionally' rammed the plane full speed into the French Alps on Tuesday, ignoring the captain�s frantic pounding on the cockpit door and the screams of terror from passengers, a prosecutor said Thursday March 26, 2015. In a split second, he killed all 150 people aboard the plane. (AP Photo) NO SALES

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More details of the mental health background of Andreas Lubitz, the co-pilot who investigators said intentionally crashed a Germanwings flight earlier this week, are coming to light.

According to the Associated Press, Lubitz had apparently hid his illness from his employers.

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Investigators found a doctor's excuse in his home that was dated for the day the plane crashed into the French Alps.

All 150 people on board were killed.

Ralf Herrenbrueck, the prosecutor's spokesman, said in a written statement that the notes were torn-up and "support the current preliminary assessment that the deceased hid his illness from his employer and colleagues," the Associated Press reported.

German news described Lubitz as a man with a history of depression  and who had received psychological treatment.