As it is not possible to eat someone without either killing them or doing them a dire injury, I think that making a threat to eat someone is a clear threat to commit murder or some other serious assault. Thus the man should be charged with making a threat of violence against the policeman.
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Health is a state of physical, mental and social wellbeing and not merely the absence of disease or infirmity
I am not a jigsaw, I am a free man !
Diagnosed under the DSM5 rules with autism spectrum disorder, under DSM4 psychologist said would have been AS (299.80) but I suspect that I am somewhere between 299.80 and 299.00 (Autism) under DSM4.