Yall, hate to tell you, but it's because of University Medical Center being open. Massive and modern facility for treating shootings immediately next to most of the high-crime areas.
It's the same as it ever was, just less bleeding out because the best hospital is now down the street.
Do I have data for this? No, not at all. But it seems pretty obvious.
Edit: Should add, "hate to tell you" is in regards to the effect on the crime rate. I don't hate to tell you all that it's saving lives-that's obviously really good.