It's been a banner year for reckonings in the St. Louis Metropolitan Police Department, and amid stories of bad cops making bigoted Facebook posts and other bad cops bragging about beating protesters, it was the voice of a good cop, Sgt. Heather Taylor, which rose to meet the occasion. Are there white supremacists on the police force? "Yes," she said, shocking a CBS News reporter with the speed of her answer. She finished the interview by blasting the department's "optional" implicit bias training. Taylor is blunt, to be sure, but her activism isn't the same as those who take to the streets to protest the police. Taylor is a twenty-year veteran of the force and the president of the Ethical Society of Police, which represents a membership primarily of black officers in the region. In that role, Taylor has walked a narrow line between cop and activist: One week she's blasting a police shooting as a murder, the next week she's tweeting heartfelt reflections about child homicides or an officer killed in the line of duty. In Twitter threads, she describes the experience of confronting armed suspects and refusing to shoot, and, in other cases, facing protests herself for her actions on duty. "We've murdered innocent people," she wrote of the department, "but not all police shootings are murder." It's not a message you'll find on protest signs or in a pro-cop Facebook page. For Taylor, though, being the conscience of the St. Louis police force has taken its toll. In a September tweet, she announced her plan to retire in 2020 and cited the ethical intransigence of those who "refuse to fight for what's right and call out wrong whether it's an officer or citizen." Taylor may be leaving the department, but she's leaving behind an example for everyone, those with badges and without. She's shown what it takes to protect the innocent and serve justice, a combination of an activist's courage and a cop's ethics, an activist's outrage and a cop's understanding. In Taylor, those elements combined into that thing every city needs more of: a force for good.