Alan Beaman’s second trip to the Illinois Supreme Court, a decade after the high court threw out his murder conviction and 50-year prison sentence based on the state’s failure to hand over a strong set of exculpatory evidence, generated a stack of amicus briefs on an important dispute — the correct standard for determining when police officers are subject to liability for malicious prosecution.McLean County prosecutors declined to retry Beaman and he received a certificate of innocence plus a pardon based …