New York hijack planned in 1999, says prosecutor
And federal prosecutor Kay Nehm said the Hamburg-based hijackers began planning an attack on the US using aircraft at least as early as October 1999, and had decided on their target six months later.
Announcing charges against Mounir El Motassadeq, the only person in German custody in connection with the attacks, Nehm said hijacker Marwan al-Shehhi mentioned the World Trade Center explicitly as a target in a conversation with a librarian either in April or May 2000.