十人遇难一警殉职，一周内二起大规模枪击案，美国再降半旗(11)

3、https://www.nytimes.com/live/2021/03/23/us/boulder-colorado-shooting?
4、https://www.cnn.com/us/live-news/boulder-colorado-shooting-3-23-21/index.html
5、https://thehill.com/homenews/senate/544486-senate-judiciary-chairman-said-he-cant-keep-up-with-number-of-mass-shootings?rl=1
原标题：《十人遇难一警殉职 一周内第二起大规模枪击案 美国再降半旗 枪手被控10项一级谋杀》