You can't make arrests on a case by case basis by thinking about it in this context. Perhaps give the aggressor a questionnaire before wacking them.
By using the term 'aggressor' you've just said that the assumption is that the black community are the ones to have caused the problem.
I'm saying the reason that that has occurred could be for a number of factors.
For example, if an institutional bias in the police results in more black people being stopped and more frequently, the willingness to co-operate erodes and the black community start to resist or be more problematic, fed up of the situation. Thus the police end up being more heavy handed and start thinking black people are far more troublesome and approach altercations with the black community with a heavier hand to start with, expecting it will be needed. This makes the black community even worse, resulting in an even more heavy handed approach, leading to more distrust and so on in a vicious circle. All started due to discrimination in who and who doesn't get stopped due to racial profiling.
Of course there will also be wrong'uns who will use that narrative as a defence when in fact they were problematic and caused the escalation.
It's not a simple "black people require more heavy handed policing ergo it's the black people causing the problem". It'd be like saying in Nazi Germany "the Jews are more likely to resist arrest and require heavy handed policing. So the Jews' are the problem"