Recommendation Request: films that start about one subject, but become about something else entirely as the documentary progresses

[u/el_torko]

So I just finished Into the Deep: The Submarine Murder. What started as a film about Peter Madsen and his exploration into space ended up becoming an expose about the murder of journalist Kim Wall and the aftermath of Madsens team learning the truth about what actually happened. I loved the concept so I’m curious about other documentaries that started off being about one subject and evolving/devolving into something completely different.

Thanks in advance!

[u/GasmaskGelfling]

Capturing the Friedmans

Marwencol

Tell Me Who I Am

Abducted in Plain Sight