From Governor Rick Perry:
The President has issued an order lowering the flags to half-staff immediately. All state agencies should display the US and Texas flags at half-staff through sunset on Friday, September 20. Other agencies, businesses and individuals are encouraged to do the same.
Flags should return to full-staff the next day. A copy of the President's proclamation appears below:
As a mark of respect for the victims of the senseless acts of violence perpetrated on September 16, 2013, at the Washington Navy Yard, by the authority vested in me as President of the United States by the Constitution and the laws of the United States of America, I hereby order that the flag of the United States shall be flown at half-staff at the White House and upon all public buildings and grounds, at all military posts and naval stations, and on all naval vessels of the Federal Government in the District of Columbia and throughout the United States and its Territories and possessions until sunset, September 20, 2013. I also direct that the flag shall be flown at half-staff for the same length of time at all United States embassies, legations, consular offices, and other facilities abroad, including all military facilities and naval vessels and stations.