Dublin police arrested Hyunwoo Lee, 34, of Dublin, Sunday night after he admitted to physically abusing a juvenile, according to police.
Lee, a self-employed tutor, reportedly housed teenagers from South Korea on student VISAs that wanted to study in America, according to police.
The investigation revealed Lee physically assaulted the victim with a stick while forcing other students to watch -- and sometimes participate, police said.
Police said Lee may have been involved in multiple acts of violence in both Dublin and San Ramon between 2011 and 2012.
Lee was booked into Santa Rita Jail and charged with two felony counts of child abuse and one felony count of assault with a deadly weapon, Alameda County District Attorney's Office spokeswoman Teresa Drenick said.
Lee was arraigned on Tuesday, and is set to make a plea at the Glea-Schenome Hall of Justice in Pleasanton on Friday at 9 a.m.