Reconstructed from the tilt-up in this news clip: http://abcn.ws/HYKKMR
Click on the photos to view them at full size.
I am convinced this photo has been edited. The black area under Zimmerman’s left ear has been painted in to cover something, probably something on or in his left hand. It is solid black with no variation in tone, and there is no black on Zimmerman’s jacket.
Just to the left of the black patch, an area on the ground appears to have been obscured by the use of Photoshop tools: Clone and/or Blur. Here is a detail enlarged 4X and with the midtone levels brightened to make the pixel pattern more apparent. The enlargement was done without an interpolating resampling algorithm (i.e. I used “nearest neighbor” in PS). The suspicious area is inside the red box. Note that the lower right corner of this area has a corner that bleeds over onto the sleeve on Zimmerman’s jacket.
In response to willisnewton’s argument that the black patch may be an authentic shadow:
Here is the photo with the midtone levels brightened all the way in PS:
And here is that image with the Threshold set at 1.
A natural shadow in that position in the frame would not stand out like that under this manipulation, nor have such clean edges.
And here is what the cuffs of GZ’s jacket look like under even indoor lighting: