His classmates must have been warned not to talk by their parents. That's all I can think.
Even N's classmates have been very silent, except for the handful that have finally started to speak up.
Maybe Greta can track down some of J's pals at school and dig in a little. Somebody's got to talk if she goes after them.
That's what I'm thinking too. Do you remember hearing about Joran having to take anger management classes? Palladin mentioned it in his post #425 and I'm wondering if it is a fact or a rumor.
"Freddy" from most of JvdS's website photos would be the first guy they should talk to... looks like that guy is his drinking buddy.