Way better to rely on actual evidence and not hunches, even more so when it comes to giving someone a prison sentence.
Real life is full of things you absolutely should do which are sold up and down through media as "looking guilty".
The best way to catch liars is to know things they don't know and trap them with that. In Among Us, it could be as simple as two people saw each other do a visual task (one that proves they're not an impostor) then have someone accuse the wrong person, or worse, be the only person that wasn't cleared that's left.
We started out realizing how difficult lying really is. The early games definitely were characterized by just people not able to hide their lies (maybe we were not trained at it ;)).
But after some training it becomes easier to lie, and of course more difficult to spot.
We also sometimes play it with my kids and those from my buddies, but they have a hard time lying, basically partly admitting when they are accused.