Poverty can breed crime. Much of the black community is still playing "catch up" to the rest of the nation and I think that's why a good deal are poor. Also, poverty is difficult to break out of.....it affects not only your circumstances, but it affects your mind as well. Our brains tend to work against us when in that situation, as well as society in general. (That's why it's so hard for homeless people to get work, society literally requires them to spend money in order to be able to get work--need money to afford hygiene supplies and decent clothes, for one, and that is just in addition to needing a home address to get things you need like an ID.)
Poverty can be generational, too, for these reasons.
This leads to stereotypes and stuff, which our brains latch onto even if it's not intentional. It's why police look at certain behaviors and looks (for example, things that look "ghetto") and profile based on that. Even when it isn't correct to do so, or that they would be more likely to pass over white people who might be guilty.
We will always have racism and prejudice, cuz that's just how humanity is. Some of it intentional, some of it not, some of it subconscious. That doesn't mean we shouldn't examine ourselves and correct others where we can when they are wrong.
I will end off with this: black people need to know that they matter to us. When we dismiss their concerns and argue with them, we are ignoring the hurt and fright they feel at the mistreatment of police to them. This is why I wear a "black lives matter" mask, despite not really supporting the organization known as BLM.