Premise: Rear Admiral Albert Jethro "A.J." Chegwidden, JAGC, USN (Ret.), is a fictional character played by John M. Jackson who is a main character on the TV series "JAG" for 8 seasons (recurring character during the first season) from 1996 to 2004, as well as making guest appearances on the spinoff series' "NCIS" season 10 finale, "Damned If You Do" in 2013, and in three episodes on the of "" in 2017.
Hypothesis: John M Jackson was played by Rear Admiral Albert Jethro "A.J." Chegwidden, JAGC, USN (Ret.)