Along with what ROS is saying, in addition to being just another name for an investigator, some agencies use the Inspector title for specialized positions. I think the NYPD uses them for some high-ranking positions. We (the USMS) uses the title for specialized (promotional) positions, such as Witness Security, Judicial Security, Technical Operations, OCDETF, etc.
We bring evil things to evil people, kicking in a door near you!
."In theory, there is no difference between theory and practice. But,
in practice, there is."
- Jan L.A. van de Snepscheut
"The difference between 'involvement' and 'commitment' is like
an eggs-and-ham breakfast: the chicken was 'involved' - the pig
was'committed'."
-unknown
Working on a PhD in CQB one doorway at a time.
When the wolf attacks, he will find not all who run with the flock are sheep!