system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why was the 'off-camera audio' of Robert Durst not immediately evidence? Why did HBO get to create a whole show first with the evidence, then, only after it aired did Durst get in trouble?

Edit: I'm feeling like this isn't quite answered yet.
So,  you're saying that if a documentary film crew exposes evidence linking someone to a crime, the crew is not legally obligated to immediately hand over that evidence to authorities? 

Edit 2: It's explained.  The producers gave the evidence to authorities long before the show's airing.
gpt
HBO is under no legal obligation to notify the police that they have evidence.  Nor are they required to turn it over unless the police have a court order(subpoena or search warrant).

Additionally, the "off-camera audio" may not be sufficient for evidentiary purposes.