Lol.   I can assure you it is the same in every state I have worked and in every state where I have known another psychiatrist.  The only exception was Nevada where I was told it was a mandatory 7 day hold for suicide threats.

However what good would seven days in a hospital do?  They all deny suicidal or homicidal thoughts in order to get discharged.  Most people with paranoid schizophrenia won't take their meds and won't go to follow up.  So you just delayed the shooting four more days by holding him 7?   Maybe you want a rule that no one hearing voices is ever let out of a hospital?  You do know that is at least six million people at any one time right?  Where will we put them?