Here is video of the protest starting at the scene of the execution and ending at Seattle city hall. The rally and march took place on September 16, 2010, starting at 2:00 p.m.
Local Native American carver,John T. Williams was shot four times at close range by Seattle police officer, Ian Birk, on August 30, 2010 at the corner of Boren Ave. and Howell St for carrying a piece of wood and a three inch folding knife.
Article here: http://www.seattlepi.com/local/426053_williams021.html
The two better Seattle news stations, KIRO and KING (in my opinion), gave the event minuscule coverage -- no big surprise.
To emphasize that there were not merely a handful of mourners participating, I start this story with video of the protesters entering city hall.