how did KID find out that Conan is Shinichi?
In Conan movie 3, Kaito disguised as Shiratori. At one scene, someone asked Conan how he knew about Scorpion. Conan didn’t answer, but Shiratori said something like Conan might have known it from Dr. Agasa. So, if Kaito knows about Dr. Agasa, it’s possible that Kaito has been to Dr. Agasa. Then, it’s possible that he found out everything from there.
