The chemistry of the murder victims’ teeth tells us these men were raised in the same region where they were buried, but spent a lot of the lives far away.  When they came home, their people were apparently not happy to see them. Notice that from the positioning of the skeletal remains, the men appear to have been hurled into the grave.  California’s native peoples traditionally went to great effort to properly bury their dead loved ones.

http://westerndigs.org/mass-grave-of-prodigal-sons-in-california-poses-prehistoric-mystery/