What is the IQ level below which one one is not to be held responsible for their crimes?

Why are we not testing every 8th grader in public school for IQ?

Why are those who would be exempt from criminal law not registered and either marked (again...) or segregated from the rest of society?

Why are we allowing these violent threats to not only move freely amongst the populace, but also condeming anyone who err on the side of caution by avoiding the most likely threats?

What is the IQ level below which one one is not to be held responsible for their crimes?

Why are we not testing every 8th grader in public school for IQ?

Why are we allowing these violent threats to not only move freely amongst the populace, but also condeming anyone who err on the side of caution by avoiding the most likely threats?