Yes they do. It's just that they do not happen so often as Black on Black crimes occur, and there is no seeming hypocrisy like that with the grievance "Black lives matter."
Do you not understand a criminal killing someone and they both happen to be black versus our government (the police) killing black people who are most often unarmed, some running away, some in their bed sleeping because the police were at the wrong address, another in his own home chilling which the off-duty but in uniform police officer allegedly mistook for her own, etc. are not the same thing, not even close.
Black people in society are more severely punished for offenses some of which are not even crimes, rarely given the benefit of the doubt even in situations where the alleged "facts" as they're being relayed to the officers don't make sense and are generally viewed by law enforcement at all levels, security personnel and a significant number of members of society with suspicion.
The white racist will tell you that the suspicion is directly due to the behavior of blacks while completely ignoring the centuries of policy, legislation, court rulings, alleged "scientific studies" and just plain ole propaganda alleging that black people are more criminally inclined and violent than whites and use this as justification for continuing the killings and violations of rights.
There is all kinds of crap going on that is not legal nor constitutional. All of the U.S. Message Board posters cheering when people are run down by vehicles that are where they're not supposed to be, wanting protestors shot for execising their first amendment right to petition the government for a redress of grievences and they call themselves patriots.