DETROIT — A northern Michigan man accused of threatening President Joe Biden and Vice President Kamala Harris was released Friday after a federal judge dismissed a criminal case that drew national attention. After a preliminary examination in federal court in Bay City, U.S. Magistrate Judge Patricia Morris concluded probable cause did not exist and that social media posts attributed to Prudenville resident Russell Douglas Warren, 48, did not pose a “true threat.” The posts included saying Biden had been condemned and called on the president to be taken to prison “to await execution. He shall b…