Autopsy to be done on man who died after minor league baseball game contest.
The event drew comparisons to the 2009 "Miracle on the Hudson."
Gunman opened fire on officer in the Nicetown neighborhood.
Online posts refers to specific terms used by EMTs and other medical professionals.
Bloodied up volunteers acted as screaming victims.
The equipment includes armor shields, rifle plate vests, and ballistic shields and helmets.