In 2006, Cariol Horne, a black Buffalo police officer, intervened when a white officer, Gregory Kwiatkowski, had a black suspect, David Mack, in a chokehold. Horne jumped on Kwiatkowski’s back to prevent him from harming Mack. In 2008, she was fired from the Buffalo Police Department for her intervention in that case and lost her pension.

https://www.cityandstateny.com/articles/policy/criminal-justice/black-buffalo-cop-stopped-another-officers-chokehold-she-was-fired