Cases like Rodney King, Oscar Grant, Eric Garner and Michael Brown have helped fuel demands for police accountability. We are joined by a guest who has advice for the growing number of people filming police abuse with their smartphones and video cameras, particularly with respect to how to properly preserve such video. Yvonne Ng is senior archivist for WITNESS, a group that trains and supports people using video in their fight for human rights. She co-authored their resource, “Activists’ Guide to Archiving Video.” Watch part two of this interview.