Shinichi would likely find out rather swiftly and he'd help Ran cover her identity. Kogoro would cause absolute chaos since he isn't as tolerant as Shinichi's parents, and if he went too far, might even get himself killed. There wouldn't be many cases and if there were, Shinichi would have to go with Ran to help Kogoro solve them, which would further increase Kogoro's suspicions. A shrunken Ran... *shakes head* wouldn't be good at all and they'd probably be killed by the BO before long. Though the idea, I was thinking of writing something similar for a fic...