The Chimu culture was esponsible for this mass murder, it was a predecessor of the Incas. The massacre happened between 1200 and 1400 ce, before the first Europeans arrived.
As Driscoll writes, sites such as these don't fit the narrative of the peaceful, noble native and the evil European invader. There was plenty of really ugly behavior by all sides, not just the Europeans.
Tyler O'Neil writes at PJ Media documenting examples of human sacrifice in many cultures:
Human sacrifice is tragically common in ancient cultures. Its eradication is one more reason why the Western heritage should be celebrated, not demonized.