all this, but also, "tried for child pornography" can mean a lot of things! It can mean "received a sext from your underage girlfriend" in some states, for crying out loud. And since LW's sister is presumably a child, there's reasonable odds that LW's partner's brother is himself pretty young.

Not all people who've dabbled in what we umbrella as "pedophilia" are Princes Andrew or Marvin Minskys.