Bit of a misleading title, I’ve not watched the video but based on the video description and article they cite (also written by them, I think?) it should read “95% of Deaths from Extremism [in the past decade] in the U.S. are [Committed by] Far-Right”. The title as it is now suggests 95% of people killed were far-right, not that 95% of people killed were killed by far right.
Personally I’d swap “are” for “were” too. Present tense is a bit of an odd choice since it’s data from the past, for obvious reasons.