I kind of like the style of writing the thoughts and feelings of many of the characters, most of which aren't the protagonist.
The problem arises when some of these characters are hiding a certain secret from the protagonist, the general public and the reader, which one of them will reveal or be found out at a dramatic moment.
This seems like it would be a bit off to me, because if the reader is "inside their head", surely they would be privy to this piece of information. However, I do see a similar thing done in, for example, in movies / TV shows, where the camera will follow a character giving the impression you have their perspective, but not reveal something important they've seen - perhaps saving the surprise for later on.
But I feel like, when writing for readers, since I'm writing the actual thoughts of this character, this shouldn't be done.
Should I just avoid writing from the perspective of this character?
But even then, what about a conversation between two such characters? i.e. Two characters know something, and are having a private conversation. This secret may be on their minds, the conversation may even be loosely related to it, but they don't speak it out loud. Would this feel almost like the characters themselves are trying to hide it from the reader? Does it behoove the author to reveal it at this point?
(to elaborate in response to comment)
Alice is the lead detective investigating a murder. However, it will turn out she knows all along who did it, and it's her friend, Bob. Now she can't find any evidence that doesn't implicate Bob, and she wants to protect him, so to everyone else the murder remains "unsolved". So her short-tempered sergeant1 enters and gives her an earful because of the lack of progress in the case. Now, can I write from Alice's POV, to portray her hatred and contempt for her annoying and ignorant sergeant, as well as the stress she's under, without revealing to the readers that she knows it's Bob?
Let's say I don't. But later, Bob and Alice are having a conversation, where Alice is ranting about her sergeant and the aforementioned altercation. Now, she has no specific reason to say out loud, "blah blah blah... the murder, which you committed", but wouldn't it be a bit dishonest of me, the author, to leave out this particular piece of information during this conversation, even if I'm not writing the thoughts of either character?
1 Apologies if I am mixing up my ranks, I'm assuming the sergeant is the detective's boss...