Update to my original post regarding the apparent killing of all eye witnesses and the absence of any wounded victims:
Two percipient witnesses, including one who sustained gunshot wounds, who saw the shooter have appeared.
(1) A Sandy Hook School staffer named Natalie Hammond was with the Principal and School Psychologist when the three of them were confronted by the shooter who opened up killing the other two and wounding Natalie Hammond in the hand, leg and foot. She crawled into an adjacent room and survived.
http://abcnews.go.com/blogs/headline...r-played-dead/
(2) The second percipient, but uninjured, witness was an as yet unnamed 6 year old girl who "played dead" while here class mates were shot to death. Presumably she had her eyes closed while "playing dead", but she would most certainly have seen the shooter burst into the room.
http://abcnews.go.com/blogs/headline...r-played-dead/
This still amounts to a fatality rate of approximately 92%...higher than any other known mass shooting. Thus far the two reported surviving eye witnesses have confirmed reports of a single shooter.