Oh, OP. Molesting teachers are not common, but they do reside everywhere--including private. It has nothing to do with private/public. See here for one example:
http://www.nytimes.com/2012/06/10/magazine/the-horace-mann-schools-secret-history-of-sexual-abuse.html?pagewanted=all&_r=0
Pull your kids out of private school.
That's not a proper way to handle life's predators and to teach your children what to do. Private school is great, but "I'm trying to keep my kids from getting molested" must be one of the less-defensible reasons to go private.