Has every witness in Dealey Plaza been identifiedNot at all. You may call them witnesses or you may call them bystanders.
The Umbrella man was identified in the 70's and testified at the House Select Commision on Assassinations
(https://sites.google.com/site/jfkforum/tum/tum-witt-grant-temple-hair.jpg)
Witt had a strong physical resemblance to TUM.
(https://sites.google.com/site/jfkforum/tum/curbstone.png)
Witt was standing on top of the sidewalk's inner curbstone, which he called a "retaining wall." Critics mistook this term to mean another place in the plaza.
(https://sites.google.com/site/jfkforum/tum/wall/holdingbackearth.jpg)
Above: The inner curbstone controlling soil slippage.
(http://i66.tinypic.com/qz5189.jpg) (http://i67.tinypic.com/hurk93.jpg)
The umbrella rotates back-and-forth on its spindle as the car goes by, meaning Witt was having trouble keeping the umbrella steady in the wind.