My knowledge is from personal experience with some that had been AWOL for a good length of time and were called deserters by the folks whose job it was to hunt them down.
At the time,I couldn't understand why the Military didn't jump at the opportunity to make examples of them.....except for the reasons explained.
A soldier or airman who has been declared AWOL (Absent Wiithout Leave) or in the case of the naval srvices UA (Unauthorised Absence). After thirty days their status automatically reverts to that of Deserter.
In the avst majority of cases the military elects not to try to apprehend AWOLS or Deserters due to the time and expense involved.
All deserters are posted in the NCIC files as such. If they are stopped for a traffic ticket and come up hot as a deserter they are apprehended by the local police and eventually returned to military control for prosecution under the UCMJ.
Until their status in the NCIC ecords changes they remain wanted men just the same as if a judge had issued a warrant.