Hi jsllim,
If you're are staff or faculty at this high school (sounds like you are from the context), you might consider acquiring the DVD referenced here: [
www.culteducation.com], and making a presentation out of it for the students who were exposed to the scientologist.
Setting the scientology exposure in this incident aside, I have that DVD and I think that it would be an excellent presentation to show all high school seniors shortly before graduation. Senior high school represents a true, perhaps last chance to do some cult education before the kids come of correct age to be wholeheartedly targeted for cult recruitment (18 - 24 years old, often college kids). The DVD costs almost nothing so you might give it a try.