Jeff -- Any death is tragic. If there is a difference in treatment, I think it has to do with that Florida law and the way the local police department handled or mishandled the case. There seems to be no question in the Chicago shootings that when apprehended, the shooters will be arrested and prosecuted. In the Florida case, I heard -- so don't hold me to this -- that the victim was tested for alcohol and drugs but not the shooter. There seems to be no question that the shooter, despite being warned off by the police dispatcher, chased the victim and confronted him. I think this is seen as related to the civil rights era in that police then not only could not be trusted to protect people of color and/or actively pursue and arrest suspects but, in some cases, were doing the shooting. It would be understandable if the victim attempted to flee. The first "race riot" in Dayton, Ohio in the 1960s followed this scenario: there was a Shriners convention in town and at 2 a.m. a couple of undercover cops wearing fezes approached a black man, said they thought he had a weapon and that he attempted to flee, so shot and killed him. The "weapon" was a tobacco pipe. And what black man would not have attempted to flee what appeared to be a couple of white conventioneers out on the town at 2 a.m. and (in the victim's mind) potentially drunk and looking to beat up a black person.
I can identify a bit with fear of police playing that role. In the mid-1960s I was dispatched to Mississippi by my newspaper just after the three civil rights workers -- Goodman (no relation) Schwerner and Chaney -- were discovered missing but before their bodies were found. I was warned by all involved in that Mississippi summer project -- white and black -- to not only not trust police there but to make sure I didn't commit the slightest traffic infraction that would give cause to pull me over. It was scary for one who had always been taught that "the policeman is my friend."
Of course, there remain isolated incidents in the north, midwest and west where cops run amok and maim or kill persons of color from a racist bent and I think a good bit of attention has been paid to those cases.
Having said all that, surely the Chicago situation -- and like ones in other cities -- are tragic and require broad-based attempts to address them.