Boston s worst crimes have her name on them. In Chinatown, she s known as Hyun Sook. At her home, she s Mom. On the inner-city ball fields, she s Coach. To her Irish-cop partner, she s Mick. At headquarters, she s Detective Li. To the killer who s carving up convicted pedophiles, and the mysterious man who s trying to snatch kids off the city s panicked streets . . . She s trouble. Mary Jo Kim is the pen name for Jo Ann Ferguson, the mother of a Korean-American son and daughter. Visit her at JoAnnFerguson.com.