RT is describing the shooter as “bearded man in his early 20s wearing all black clothing.”
Possibly Antifa or RoP....? Sounds like their usual suspects.
Could be any group.
Report from link Kstp5:
a gunman walked in with his face partly covered by something resembling a ski mask, opened fire on a person working the door, then began to shoot people at random.
Sounds like typical chaos during initial reports. Wont know until after the scene is cleared.