When a Chinese-American police officer kills an unarmed Black man in a darkened stairwell of a New York City housing project, it sets off a firestorm of emotion and calls for accountability. In 2014, Peter Liang became the first NYPD officer convicted of an on duty shooting in over a decade, inciting a complicated fight for justice wherein two subjugated communities were thrust into the uneven criminal justice system together. Down a Dark Stairwell captures both one of the largest Asian-American protests in history and a key event in the emerging Black Lives Matter movement. In this unflinching documentary directed by Ursula Liang, the insidious effects of white supremacy in American society are starkly revealed, persisting even when the participants on both sides of a conflict are people of color.