Speech bubble is a Q (screenshotted a little late)
Amazon shooter identified.
Maximum Insanity
Sicknick cause of death released
2 strokes, natural causes
https://www.washingtonpost.com/local/public-safety/brian-sicknick-death-strokes/2021/04/19/36d2d310-617e-11eb-afbe-9a11a127d146_story.html