Anyone ever find out why there weren’t any LEOs at that event?
Because none were requested, and local LE wasn’t informed of the event. It’s pretty typical, and Giffords did this sort of thing a lot. My guess is there will always be LE present from now on.
This was a "card table" event. According to reports that I have read the congresswoman would literally setup outside a store and attempt to engage people. I don't imagine that much thought was given to security.