[JoyjoyfromNJ]

No one has pointed out that pilot credentials can be stolen; see the link below. If no one knew this copilot by sight, perhaps he was killed and his credentials used by a terrorist.

http://www.justice.gov/opa/pr/iranian-pilot-sentenced-27-months-prison-stealing-us-pilot-s-identity-obtain-federal-aviation

[maggief]

Co-pilot lived with parents, keeping a flat in Duesseldorf.

I read his parents have been questioned, and police have Montabaur under guard.

[Batman11]

“No one has pointed out that pilot credentials can be stolen; see the link below. If no one knew this copilot by sight, perhaps he was killed and his credentials used by a terrorist.”

I was speculating along these lines as well. Did Lubitz fly with this particular crew before?