No they cant’t stop their female police officers from dating black guys. The controversy was that they knelt before the BLM while on active duty and wearing their uniforms. For mainstream media and mainstream politicians that was a bit much. But they will get used to it.
She did nothing wrong. When you got a system and society that is so racist and corrupt to uphold white supremacy that one of its law enforcers shows support for the voices trying to speak about the issue and she is seen as going too far or deserving some punishment, then the system knows it's wrong and can't stand criticism. This is seen in all white countries because they all got the same goal regardless of their history of preserving their own power, supremacy and comforts over everyone.There was an internal investigation that said that the actions were inappropriate as they did not follow the constitutional requirement to act impartially toward the protest. But they suffered no consequences.