My gut says
US Army.
USAF has some C-12s, but they are painted differently and on embassy transport duty in Europe (at least I think so, could be wrong). Plugging the tail number into Scramble (scramble.nl) and assuming that the first (typically omitted) number is
8, 86-0088 returns nothing. Often, though, a
0 is omitted in Army tail numbers. 86-00068 returns the following:
Type: C-12T-2
CN: BP-68
Unit: OSACOM Det.8
Comment: FL ARNG (Florida Army National Guard
Trying another site,
http://home.att.net/~jbaugher/ , the numbers 6-0088 returns:
86-0084 ... 86-0089
Beechcraft C-12F Huron
c/n BP-064/069. These have also been reported as C-12Js with c/ns UD-007/012
Using 86-0088 returns the same information as above. Using 86-00088, returns nothing.
Make Orwell fiction again.