There has to be more to this than what is known. A person does not turn into a murderer and kill unarmed people when faced with the circumstances that this man faced.
I am sure that there will be a major investigation into the complete circumstances surrounding this event. Until that investigation is complete, all statements concerning the mental state of the victims and suspect are just theory.
I do know that people who panic, lose the ability to defend themselves effectively. Also, as evidenced in many law enforcement shoot outs, a well armed suspect who does not fear death, has an advantage over his opponents. If he had been carrying a single shot 22, I doubt that the results would have varried all that much.
C F
C F