I am not sure what this means about the other image that was circulating (possibly the wrong pic?), but the image below contains the new picture being circulated.
Also, live feed of the MPD press conference is available here. The press conference is no longer on the air.[EDIT – Sheek, 12:50 pm]
It seems that the other picture was a Cornell professor with the same name, totally unrelated to any of this. Apologies to him – Professor Stephen Morgan of Cornell is most definitely not an armed gunman.
Campus Security has a clearer picture of this Stephen Morgan: