Did you watch the trial or even know the evidence of the KR case? There was no vigilantism at all. Kyle was one of HUNDREDS carrying guns for protection that night. Many were also protestors doing so legally. It was the 5th night where previous nights had seen quite a few buildings burned down. He was out the 4th day and the 5th cleaning up streets of graffiti and trash. On the 5th day, the guys from Car Source ask if he and friends wouldn't mind cleaning around their place and maybe help out in being around to prevent further arson that already burned one of their lots down. Carrying a gun is not vigilantism. He along with many others from the area or in nearby communities all pitched in that night to help keep places from burning down with their mere presence. Which is why the 5th night had no burned down buildings. It was also the last night of the riots as well there during that time for that reason too.
By all the evidence, Kyle was ambushed, attacked, and was forced to defend himself when he used every opportunity to defuse situations or flee. That is not vigilantism. For reference here is the definition of that.
a member of a volunteer committee organized to suppress and punish crime summarily (as when the processes of law are viewed as inadequate); broadly : a self-appointed doer of justice… See the full definition
www.merriam-webster.com
He was not trying to capture or punish anyone for any crime at all during the 2 days there. Self defense when people attack you is not vigilantism. It is literally ludicrous to think that at all.