At least one dead, four wounded:

http://abcnews.go.com/US/wireStory/police-shot-zombiecon-34551452

More:

http://m.nydailynews.com/news/national/hundreds-flee-florida-zombicon-shooting-kills-1-wounds-4-article-1.2401757

Tragic. No other words. 

A bit more:

http://talkingpointsmemo.com/news/zombicon-shooting-florida

WTOP Newsradio in the Nation's Capital reports that four hours before the time of the shooting, a Fort Meyers newspaper website had posted as a headline: Dead Come To Fort Meyers Plaza. It was quietly removed.

UPDATE:

Now the deceased has been identified, wounded count raised to 5.

Much more here:

http://www.abc-7.com/story/30288053/police-1-dead-4-injured-in-shooting-at-fort-myers-zombicon

This is really sad and tragic. My thoughts and prayers go out to the victims