My understanding is that the shooter is not clearly identifiable, but people that night were bragging on Twitter about the "beautiful shot placement" by "security on the ground": https://twitter.com/EffInvictus/status/1277828963369353216/p...

Video taken in the aftermath captures people discussing how they will collect and hide the evidence. Seattle Police found and questioned the woman who filmed that video, but she told them she didn't know anything: https://www.seattletimes.com/seattle-news/crime/woman-releas...