cook county judge dennis porter , cleared 46-year-old officer dante servin in the march 2012 shooting death of rekia boyd , 22 .
moments before he announced the verdict on monday , he asked loved ones who might be prone to outbursts to leave the courtroom , fearing there would be an emotionally-charged response .
boyd was standing with her friend antonio cross , who reached into his waistband , pretending he had a gun , and charged at servin , the court heard .
she was gunned down on march 21 as she stood with friends outside a property in chicago 's lawndale neighbourhood .