The first time I heard this report (on our local Southern Orgeon evening news program), the fact that the step-mom claimed the boy disappeared while on his way to class struck me as odd, since it left open the question of how did she know he was walking to class when, according to her story, she'd just dropped him off at school.
This story has gotten a lot of coverage here and--sad to say--the growing suspicion regarding the step-mom does not surprise me. And that's just sad!