 It's an appeal that Tabitha Wanjiru hopes the police will heed as she goes to court to compel the police to fully investigate his son's disappearance. I am asking you, Joseph Mwangi Kairu, wherever you are, please come home. If you can't, she sobs. If there's anyone detaining my son, please release him. Let my son go. For NPR News, I'm Emano Ligunza in Nairobi, Kenya.