Need ID help

[MVandoren1]

Hi-
I'm new to this forum and wanted to ask a question concerning who (Agency, etc.) uses the following type of vehicles. In this case a friend spotted these hitching a ride on one of those vehicle delivery semi's. Tihs groupng consisted of several vehicles, the first was apparently an H1 military with the gun turret on the back end. Accompanyinh that were 2 chevy Impala's and one or two Suburban style vehicles. Now each of these were a spotless white with a red stripe going accross the hood and angling down over the front door. Somewhere in this array of color were blue stars and over the door were a large, say maybe 18" or larger diameter silver badge. Each vehicle was equipped with chrome bumpers, chrome running boards and what I'm sure is the latest in aerodynamic light bars over the top of each vehicle.
My friend couldn't make out the wording on the badges and I was hoping that maybe someone here has seen these vehicles before. What group could they belong to? If the Hummer didn't have the gun turret I'd think maybe with the red, white and blue design they could be some sort of Public Awareness division of Homeland Security or something, but what else could these be- something with law enforcement? INS border patrol???
Any ideas on finding these if no one knows of them could be a big help too- thanks