Updating the changes in DC's crime rates since Heller
What I have pointed out is that even though very few handgun permits have been issued (only a few thousand the last time that I looked), the big change in DC was the court striking down the ban on having loaded long guns in the District. It had been a felony to chamber a bullet or a shotgun shell. When the Supreme Court made its decision over 72,000 adults legally owned long guns. After the decision, they were able to legally use those guns for self defense.
Boston Globe has this story about the huge recent drop in homicides in DC, but the article fails to note that the drop started right after the Supreme Court decision. How can one write a story on this without mentioning the court's decision? The article mentions the crack epidemic. Crack was indeed a problem, but that problem ended in the early 1990s.