July 25, 2020. Sparks from a tear gas grenade rain down on shielded protesters. 2-chlorobenzylidene malononitrile (CS) is the defining compound of common CS tear gas and needs immense heat to be activated in aerosol form. Approximately 3000 Black Lives Matter protesters gathered outside the Multnomah County Justice Center and the U.S. District Courthouse in downtown Portland, Oregon, on the evening of July 25, 2020, marking 59 consecutive days of remonstration against police brutality and racism in the Rose City and across the country. The size of the protest swelled over the past week from the hundreds to the thousands as videos began to surface on social media of federal agents in unmarked vehicles wearing military cammo uniforms with no identification detaining protesters off the street. The protest Saturday evening began peacefully, but small clashes between police and protesters erupted as the night progressed. The assembly was deemed unlawful around 11 p.m. Around 12:30 a.m. on July 26, the protesters pulled down part of the barrier fence in front of the District Courthouse and the federal troops responded with a barrage of tear gas, rubber bullets, and paintballs. Protesters formed a phalanx style line with homemade shields and umbrellas, throwing active tear gas canisters back toward the federal troops, who advanced on the line of protesters with various crowd control munitions, including mace. The federal troops pushed the protesters back several blocks into the city. The protest continued past 3 a.m. and police detained several people. Photo by Austin Johnson.