[Old Teufel Hunden]

"Apparently this is the guy"

I'm not sure where you got your information, but the blogger you linked to (RWhiteman) had his home listed as Greensburg in Westmoreland County. However, this shooting took place in a Pittsburgh neighborhood which is in Allegheny County. Unless the guy had two homes, I don't see how this is the same person.

[browardchad]

This is the guy, and his buddy Perkovic, who really seems to be enjoying the publicity.  Real losers.

From Fox News:

"Poplawski had once tried to join the Marines, but was kicked out of boot camp after throwing a food tray at a drill sergeant, Perkovic said."

That was after he was expelled from Catholic high school. More info here.