Subaru Okiya
Subaru Okiya is a college student currently living at Shinichi Kudo’s house. He has been able to deduct info about certain cases like a genius detective would. This, among other reasons (most noticebly Haibara’s fear of him) has made it seem very likely that he is actually Bourbon, a new member of the Black Organisation.
In the end of episode 704 it was revealed that his true identity is Akai Shuuichi.