I take that back. I just read this article where he was seen closer to the train station looking for his car. Apparently, the guy was suffering from some sort of dementia.
http://philadelphia.cbslocal.com/2011/01/04/video-released-in-murder-mystery-of-del-war-vet/
Am wondering too; if perhaps, when briefcase was stolen - assuming it was - if he was not hit on the head by perp; which may have caused some bleeding etc; and so 'from there'.. .he went downhill. Although; none of this yet explains; how he ended up in dumpster. Was he 'placed inside', or was he confused and still 'just looking' for his briefcase. . .
Again; too bad this was not appropriately dealt with by the 'Security' when he clearly demonstrated he needed 'real' assistance.