Some newer media type was supposedly trying to get the records (if any) released.
He's had some brushes with the law in the past I'm sure, to what extent is the unknown. When he strong-armed that store clerk, I doubt it was the first time he'd used physical intimidation and threats to get his way. He's probably always been a big kid, and has bullied his way through life. From that store video, it looks like his first response to being confronted by anyone is to resort to physical violence. That's a pattern in his behavior...and wasn't just exhibited for the first time in that video.
On some of the Michael Brown threads there’s a link to some media’s FOIA request for his juvenile records. Not any of the MSM, I’d bet.