STUDIES:
547/
"[Brazilian police in simulators] shot at black targets faster than at whites when they were armed, and had more difficulty (were slower) not to shoot blacks than whites when they were unarmed." & “There were no effects of the [police] participants' color."

The Decision to Shoot Black Suspects in Brazil: The Police Officer’s Dilemma
Race and Social Problems
Vol. 10 Issue 2, pp. 101–112,
2018
Comment on this study on its Twitter thread.