By Julia Harte and Mark Hosenball WASHINGTON (Reuters) - A couple who massacred 14 people at a California holiday party were discussing martyrdom online before they met in person and married, FBI Director James Comey said on Wednesday. A U.S. government source familiar with the investigation of the shooting said Syed Rizwan Farook, 28, may have been plotting an attack on a U.S. target as early as 2011. Comey, testifying at a hearing of the Senate Judiciary Committee, said there was yet no evidence that the marriage of Farook, who was born in the Illinois to Pakistani immigrants, and Tashfeen Malik, 29, who was born in Pakistan and lived most of her life in Saudi Arabia, was arranged by a militant group.