United States National Guard

A Massachusetts Air National Guardsman arrested in the leak of highly classified military documents is expected in federal court Friday as the Justice Department prepares to outline the criminal case against him.

By the busload and planeload, National Guard troops were pouring into the nation's capital on Jan. 16, as governors answered the urgent pleas of U.S. defense officials for more troops to help safeguard Washington even as they keep anxious eyes on possible violent protests in their own states.

Police fired tear gas Monday in another night of unrest in a Missouri town where a white police officer shot and killed an unarmed black teenager, just hours after President Barack Obama called for calm.