Conan reveals that Yumi Yamamoto 's dentist assistant and deduces Yumi entered Yamamoto 's apartment and offered to treat him .
After investigating Yamamoto 's dentist , Conan tranquilizes Kogoro and reveals the murderer to be Yamamoto 's neighbor , Yumi Suzuki .
Conan reveals that Yumi Yamamoto 's dentist assistant and deduces Yumi Suzuki entered Yamamoto 's apartment and offered to treat Conan .
After investigating Yamamoto 's dentist , Conan tranquilizes Kogoro and reveals the murderer to be Yamamoto 's neighbor , Yumi Suzuki .