NCIS Character No One Remembers Is Played by Star Trek's Jonathan Frakes
Jonathan Frakes’ directorial duties are not limited to Star Trek. He has worked on NCIS: Los Angeles, Castle, Leverage, Burn Notice, and more. While he is best known for playing William Riker on TNG, he has made a mark as a director in these shows and seems to have mastered the craft, prompting shows to call him back multiple times.
Apart from directing six episodes of NCIS: Los Angeles, Frakes also had a guest role in the second season episode ‘Disorder’. He played the role of Navy Commander Dr. Stanfill in the episode, though he was left uncredited for his acting services. He has not returned to the role in the show, despite direcing many other episodes.

Jonathan Frakes has made a mark in the TV industry not only as an actor but also as a director. Frakes began his stint shadowing various filmmakers on the sets of Star Trek: TNG, where he played William Riker in the main cast. His directorials have always been highly regarded, with the time loop episode ‘Cause and Effect’ being considered one of the best.
Frakes also went on to direct episodes in Star Trek: Deep Space Nine, Voyager, Enterprise, and Strange New Worlds. He also directed the movies First Contact and Insurrection, the former of which is considered to be one of the best original Star Trek movies. He also did directing duties on NCIS: Los Angeles, Burn Notice, Castle, and more.

Frakes directed eight episodes on NCIS: LA and contributed immensely to its ratings. Apart from the first season episode ‘LD50’ and the second season one ‘Disorder’, he directed the highly-rated Christmas episode ‘Free Ride’. Surprisingly, he also played a small role in ‘Disorder’, for which he was uncredited (via IMDb).
The episode sees the death of two men in a shootout and the NCIS team’s investigation of the case with the help of a former Navy officer, who has undergone severe PTSD. Frakes played the role of a Navy Commander named Dr. Stanfill. He did not have any lines in the episode, and he was uncredited, though his directorial work was obviously credited.

As mentioned before, Jonathan Frakes has built quite a strong resume as a director on TV. His episodes have been highly rated, and he seems to be the go-to man for all experimental episodes in the Star Trek franchise. However, as much as he knows how to bend the rules, he also knows when to follow them.
There is a reason why Frakes has been called back as a director on shows like Castle and NCIS: Los Angeles. These procedurals have a set format, and anything that is different from it takes a huge toll on the production and the episode’s reception. Hence, Frakes advised that directors just go in and play by their rules. He said to NCIS: LA Magazine,
For instance, NCIS: Los Angeles, you’re hired to do an episode of that show. And that show looks a certain way, and it’s shot a certain way. You cannot go in there and reinvent the wheel. The actors know their characters…Same is true on Castle. There are three sizes of close-ups that you must get during the interrogation of Castle and Beckett. If you don’t do it, you’re just an asshole and you’re not making the show properly and you won’t be asked back.
While Star Trek takes a lot of pride in experimenting with the narratives and exploring profound concepts (the show’s format lends itself well to it), procedurals like NCIS need to be in a certain way. Jonathan Frakes described directing on these shows as keeping the train on the tracks.