The shooting did not happen at 5821 Sheridan, that building does not match the background of videos which show the first gunfire. Compare the street view of 5821 Sheridan to the background of, for example, this video.
5912 Sheridan is an auto repair shop. There were a number of young men there defending it, including a couple posted on the roof. There are also a number of times where armed young men defended the adjacent gas station on both nights of the riot.
. I looked at the business name From the video to get the address, but car source must have bought 6260 as a second or additional location. Thanks.