This week's viral videos of a Columbia, S.C., deputy's push-the-chair-over-and-drag-the-student arrest of a 16-year-old high school girl in her classroom has refocused attention on the expanding role of police in schools, "zero tolerance" discipline policies and the disproportionate punishment of minorities. The student in the case was African-American and the deputy, Ben Fields, is white.

The Richland County sheriff, Leon Lott, fired Fields on Wednesday. Witnesses say the student was disruptive and refused to leave the classroom. "What she did doesn't justify what our deputy did," Lott said. "He should not have thrown the student."

An attorney for Fields has said the deputy's actions were "justified and lawful."

NPR Ed has done lots of reporting on the racial gap in school discipline, including stories here, here and here. We've also written extensively about alternative discipline policies in schools. NPR's Code Switch team has also covered the topic.

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