The U.S. President and Idaho Governor have the authority order U.S. and State of Idaho flags to be flown at half-staff within the State of Idaho for certain occasions. 

FROM THE WHITE HOUSE: Flags will be lowered to half-staff immediately in honor and remembrance of the victims of the horrific tragedy in Uvalde, TX. The flag should be flown at half-staff until sunset, May 28, 2022.