well whatever it is, it's not a taser.
i think it's sunglasses
if Slager is planting evidence, what about fingerprints?
In the dash cam video, the officer yells, "taser, taser, taser." That is a programmed training response when employing the taser, so it is reasonable to expect that the taser is out and had been fired. Firing a taser at a moving target is way less than a 100% effective weapon. It is unfortunate that the videos don't show what exactly happened between the taser employment and the shots fired.
There was another dashcam video released today that shows another police car arriving at the scene. It doesn't show much, but does give perspective of where the stop was in relation to the shooting. A fairly small area, it wasn't much of a chase.