Military casualty reports usually contain sufficient information to determine whether death occurred in the line of duty while serving on active duty.

Obtain a casualty report from the Armed Forces branch. Unless the military casualty report clearly indicates to the contrary, assume an in-service death occurred in line of duty. If the report clearly indicates that this requirement is not met, consider whether the requirements pertaining to accidental death can be met; if necessary, get a certified copy of the death certificate if death occurred in the U.S.