The incident aftermathed in the video happened in Michoacán, Mexico. Apparently, a group of shooters barged into the video arcade and opened fire at the gamers inside. Multiple people were shot dead.
That’s all I got for backinfo, so I don’t know what the presumed motives for the slaughter were, nor how many people exactly were killed.
Best Gore member @raaleva has an update on the incident:
In Mexican news there are reports that drug dealers went to the arcade (likely to retake their territory).
There were 6 elementary school kids known as “mules” who were selling drugs for a rival. As of yet, I have not heard a total number of injured/casualties.
At least nine people — four of them minors — have been killed and two others wounded in the shooting.
The massacre happened in the city of Uruapan, home to a quarter million people.
Props to Best Gore member @gustavoavalo for the video: