PA law appears to require the consent of all parties for the interception of oral communication unless there is no reasonable expectation of privacy.
This was found on one of many sites I Googled:
18 Pa. Cons. Stat. §§ 5703, 5704: It is a felony to intercept any wire, oral or electronic communication without the consent of all participants. It also is a felony to disclose or use the contents of a communication when there is reason to know those contents were obtained through an illegal interception.
Under the statute, consent is not required for the taping of a non-electronic communication uttered by a person who does not have a reasonable expectation of privacy in that communication. See definition of "oral communication," 18 Pa. Cons. Stat. § 5702.
A trial court has held that a communication protected by the legislation is one in which there is an expectation that it will not be recorded by any electronic device, rather than one in which there is a general expectation of privacy. Thus, the fact that a participant may believe he will have to reveal the contents of a communication, or that other parties may repeat the contents, does not necessarily mean that he would have expected that it would be recorded, and it is the expectation that the communication would not be recorded that triggers the wiretapping law's protections. Pennsylvania v. McIvor, 670 A.2d 697 (Pa. Super. Ct. 1996), petition for appeal denied, 692 A.2d 564 (Pa. 1997).
Anyone whose communication has been unlawfully intercepted can recover actual damages in the amount of $100 per day of violation or $1,000, whichever is greater, and also can recover punitive damages, litigation costs and attorney fees. 18 Pa. Const. Stat.§ 5725.
A person commits a misdemeanor if he views, photographs or films another person in a state of full or partial nudity without consent, under circumstances where the nude person has an expectation of privacy.18 Pa. Const. Stat.§ 7507.1.
I would check with an attorney before you did this.
However, it would seem that your taping (at least the audio) with a dash cam unless the guard was advised of the taping ahead of time would violate that law. And if you are going to create a confrontation to prove your point you might also find yourself arrested or charged with some other offense.
Better to avoid the run-ins rather than seek one!
A Nor Cal Police Sergeant
"Make mine a double mocha ...
... and a croissant!"
Walk humbly with your God
-- Courageous, by Casting Crowns