The U.S. Air Force has released the results of an investigation into the alleged leaking of classified documents by Massachusetts Air National Guardsman Jack Teixeira, finding that he acted alone but his unit failed to take proper action. 15 personnel were disciplined for “dereliction of duty” due to their failure to properly supervise Teixeira’s access, and the Air Force has implemented additional security measures and increased oversight to prevent similar incidents in the future.