Rule 39
No such thing as a coincidence? Or is there?
My wife and I are watching The West Wing for the first time and I noticed this.
Michael O'Neill played Riley McCallister on NCIS, as a former SSA of some sort of Gibbs. He was on the episodes S8E8 Enemies Foreign and S8E9 Enemies Domestic (plus 1 more). He played secret service agent Ron Butterfield on The West Wing and it looks like he was the guy in charge of the presidential detail (like the guy who fired Kate Todd in S1E1 Yankee White).
Mark Harmon, of course, is Gibbs, a SSA on NCIS and a subordinate to McCallister in the flashback on Enemies Domestic. He had a 4 episode run on The West Wing as secret service agent Simon Donovan. He was a subordinate to O'Neill's character and protector (?) of CJ Cregg, the press secretary.
Harmon's first episode on The West Wing?? S3E18 Enemies Foreign and Domestic.
This is Lincoln/Kennedy stuff right here!