I could see putting it on the kids' permanent record - both police & school - but that's probably of minimal deterrent value for a large fraction of young kidiots*. Not that catching the perp's is any sort of sure thing, either.
It'd be lovely if one could "re-train" youth culture, to greatly reduce the impact/thrill of the crime. I'd guess that that's the only payoff for 98% of perps. But in a world where (by many accounts) kids are often routinely browsing "extreme" porn years before many of their parents are comfortable with them being taught anything more adult than "when a man and a woman love each over very much..." - it's hard to imagine that the school or authorities could actually do that.
(Any thoughts?)
*Yes, like most old men, I was once a young idiot. No offenses remotely resembling this...but that was back in the days when a line-printer-on-green-bar-paper dirty image was still cutting-edge smut.