From the caption under the photo in your link..................
DENVER, COLORADO - OCTOBER 10: A man punches another man after a rally in Denver, Colorado, on October 10, 2020. The man on the left side of the photo was supporting the "Patriot Rally". He engaged with the man on the right, hit him in the face and sprayed him with mace. The man at right, then shot and killed the protester. (Photo by Helen H. Richardson/MediaNews Group/The Denver Post via Getty Images) (Getty)
Apparently, the man and the security guard exchanged heated words, the man punched and maced the security guard, and then the guard fired their weapon, killing the man. If the roles were reversed, you right wingers would be saying that the security guard acted in self defense because a left winger maced him
By the way................this article is from October 11th, 2020, almost a year and a half ago. Why are you bringing it up so far after when it happened?