Looked more like a wallet than anything else.
Yup...the teleporting taser:
At the 1 minute mark Slagor jogs back to retrieve the taser...
at 1.30 he drops it by scott..
At the 2 minute mark you can clearly see him pick up the taser that he tossed down and holster it on his left side.
http://www.theguardian.com/us-news/video/2015/apr/08/us-police-fatal-shooting-south-carolina-phone-footage-viral-video