a little more than a name would be helpful
Mr. Jiujutsuka 8),
You should take a picture of the offender and include it in a follow up email. Names can be changed rather easily in this country, and not too many people would like to follow your chase of links simply to find some perverted freak. If he really is a sex offender, as you say, then he can't sue you I don't think...but contact a lawyer first. There's my twopence.