In the final episode of Season 1 of Dexter, Dexter finds out the truth about Brian Moser.
It is mentioned during the season that Dexter adoptive father removed any evidence of what happened when his mother was murdered, but it wasn't mentioned that he removed all evidence about the real identity of Brian.
So how come Dexter's team didn't find the truth, and thought Brian Moser is not related to him?
I still did not watch any other season, so would like to know if this is explained within the scope of season 1.