system
Given the following post, respond as if you're commenting on Reddit:
human
[Joker 2019] How in the world did Arthur Fleck...

...bring a gun on the Murray Franklin show without getting caught beforehand? Sure, I imagine security threats are not much of a problem when you're interviewing famous celebrities that have a lot to lose. But when you're bringing on some random guy from the street, one painted in clown makeup no less, wants to be introduced as "Joker" and seems obviously mentally disturbed, one would think a frisk and/or metal detector would at least be in order.
gpt
As others have said, it was the 80s. Actual hard security checkpoints to get into public areas really weren't a thing back then, especially for invited guests in backstage areas. Metal detectors and the like were expensive, specialized hardware, and chiefly limited to real "high security" areas, like courthouses and airports; a random TV studio likely isn't bothering with that sort of hardware.