Robbery in the second degree.
569.030. 1. A person commits the crime of robbery in the second degree when he forcibly steals property.
2. Robbery in the second degree is a class B felony.
http://www.moga.mo.gov/statutes/C500-599/5690000030.HTM
With the CCTV footage from the convenience store, I think he would have been charged and convicted of felony robbery - especially if the store clerk who he assaulted testified.
Of course he would have been charged with a felony. It's on tape. The Prosecutor isn't going to cut a <mod snip> any slack. I think he would be convicted on the basis of the video and other witnesses. The shop clerk wouldn't have to testify. I think these <mod snip> had been intimidating that clerk for a long, long time. He didn't call 911, some other customer did.
JMO