It's Scott Bakula on NCIS! He portays a former colleague of Gibbs.
Added:

NCIS Season 11 Episode 18 Quotes

Pride: Laissez les bon temps rouler.
Gibbs: Let the good times roll.

Bishop: Where can I sit? Is the floor clean? Do you have any sugar? Lots of it?
Brodie: Err.
Lasalle: Huh?
Brodie: Three-letter word for mistake. Err.