A middle school teacher at Hempstead's Alverta B. Gray Schultz Middle School was in a classroom Wednesday afternoon when a parent went past a security checkpoint and waited outside her door to confront her, police and union officials said. The parent, later identified as Annika McKenzie, 34, insisted in engaging the teacher for reasons that haven't been disclosed. The teacher was heard asking the woman to get a security pass and then calling for security before things got worse, police said.