Why do you feel the need to tell us that you don't care about the victim, is what people are getting at. It distracts from the point, which is that the police officer in question acted heinously. Because it distracts from that point, it comes off like you are excusing him, even though I recognize you acknowledge that he deserves to be punished.
The victim's record doesn't matter, it wasn't relevant to the situation or to the larger context that this kind of police brutality is all too common in the US.