According to the info I got, the killers in the video are members of the infamous Comando Vermelho (Red Command) gang from Brazil. The handsign shown on camera at 0:35 seems to confirm that. This faction of CV must have uncucked itself somehow.
The video shows the presumed CV members stabbing a woman to death in some backwoods area at night. The stabbing is relentless, targeting primarily the woman’s neck and head areas. As far as biceps workout is concerned, I’m sure this Brazilian maximum gain method is effective, if not a tad extreme.
Props to Best Gore membere @BoscoTkc for the video: