According to the official of the Georgia DOC (I didn't get his name) they were being transported to a "Diagnostic Facility," he stated that that facility was a "hub" to which inmates are transported before taking them elsewhere.
The Georgia DOC guy said the two inmates did not know in advance when they were going to be transported.
Also, a correction has been placed on the ABC News site, to the effect that the weapons are 9mm not .40 cal (I don't think there's any substantial difference).
Seems to me that a LWOP prisoner, deemed a “monster” by the prosecutor, should be kept where he is. Or given special transport, like in an armored car, in a straight jacked, wrapped in chains.
Seems like they were treating him like some kind of prisoner day laborer.