Or, maybe the IISS security branch is more like Interpol?
Anyone?
I would say that mostly they are, but they do still have a small cadre of door-kickers, who are really for special projects, like grabbing their own from the clutches of Evil-doers. The Interpol hat nests well with their Intel functions. Essentially you have those doing law enforcement Intel, focused on interstellar connections of non-imperial violations.
Mostly, they just hook up either the locals, MoJ, IN, or subsection navy.