Killer At Large?

Riddle: A young man named Orion is carrying a large, double-edged axe. He is stalking his prey, possessed by one single thought -- to kill! His hands are calloused, but his soul is not, as he always strives to be kind to others, despite his strong desire to kill. He has killed 11 times already today, but he feels compelled to kill at least two more times because that very morning Orion believes he heard a voice instructing him to kill no fewer than 13 today. Orion plans to use his axe to kill only those older than 50 years of age. Many other people have witnessed his multiple axe killings, but no one has ever tried to intervene or report his actions to the police. What is wrong with these people? It appears obvious that Orion is seriously mentally ill and suffers from auditory hallucinations with delusional thinking. How can his killing spree possibly be ignored? Or, is there some reasonable explanation for these events? Just what in the world is happening here?