You guys are silly. There are no anti-terrorism cops at PKI or at least that I know of. Like it's already been stated again, and again, the guys you see wearing the Black shirts, with the 7-point deputy sheriff badges that says "Park Police" on it are PKI park police officers and have arresting (ie. meaning they can arrest for any violation of the Ohio Revised Code) powers on park property. They are properly trained and certified just like any other police officer, that's why they carry guns, mace, asp, handcuffs etc. I think even some of them might be police officers in other towns that they live in. Now as for other police agencies. Again, as stated before , PKI does fall within the boundaries of the City of Mason, and Warren County. So yes PKI is within both of their jurisdictions. So if something serious is going on, you might plan to seen those people at PKI. And Deerfield Twp PD and Warren County Sheriff is the same thing. I do believe as well that there is at least always 1 Mason police officer at PKI during hours of operation. As for OSP (Ohio State Patrol) not sure why they'd be there. *shrugs* From what I gather they only have authority on state property. And as for the "plain clothed" officers. Just sit and think a minute on why there would be Park Police officers in plain clothes. Eventually, you might figure it out. Key word "might."