Trump administration officials say the Air Force didn't submit the accused Texas church shooter's criminal history to the FBI, as required by Pentagon rules.
The officials were not authorized to discuss the matter and spoke on condition of anonymity.
Devin Patrick Kelley was convicted of assault in an Air Force court martial in 2012 and given a bad conduct discharge in 2014.
He is the suspected gunman in the attack Sunday in Sutherland Springs, Texas, in which 26 people were killed.
Under Pentagon rules, information about convictions of military personnel in crimes like assault should be submitted to the FBI's Criminal Justice Investigation Services Division.