Malcolm Gladwell had a series on guns for his Revisionist History podcast a little while, and episode four ("Moral Hazard") found some interesting numbers:

* https://www.pushkin.fm/podcasts/revisionist-history/guns-par...

* https://www.youtube.com/watch?v=pl7c_O_XtfU

From the transcript:

> Now, think about the implications of that in a place like Washington, DC. In the last 30 years, the number of homicides in Washington in a typical year has been cut in half. People look at that statistic and say, "Oh, the city's gotten a lot safer." But isn't some part of that decline simply that Eddie Cornwell and Mallory Williams and all the other trauma surgeons of Washington, DC are now saving lives that were once lost?

> A city's murder rate is not a measure of the number of people victimized by potentially lethal violence. No. It's a measure of the number of people victimized by potentially lethal violence minus how good a job doctors do at saving that person's life once they get to the hospital.

[…]

> And what they found is that every way you look at it, gun violence in Memphis got worse in that period. The number of gunshot wounds they saw increased. In fact, the number went up 59% just between 2010 and 2015.

> The severity of the wounds they saw got worse. The number of people being wheeled in with multiple gunshot wounds more than tripled. In absolutely every sense, the patients coming into that hospital in those years showed that Memphis was becoming a dramatically more dangerous place.

> But what happened to the mortality rate of gunshot victims coming into that hospital during that period? It went down. It dropped by a third. The trauma doctors at the University of Tennessee Medical Center are so good that they made the increase in bloodshed on the streets of Memphis all but invisible.

> So what does the homicide rate in Memphis tell us about the level of violence in Memphis? Nothing. That's implication number one. We probably should stop using homicide rates as a measure of how safe and healthy a community is.

He interviews trauma surgeons, but also researchers looking at this statistics, like Natalie Hipple:

* https://news.iu.edu/live/profiles/975-natalie-hipple

Medical care then connects into episode five ("The Footnote") of the series:

* https://www.pushkin.fm/podcasts/revisionist-history/guns-par...

* https://www.youtube.com/watch?v=sNGIU1CKpnY

From the transcript:

> [Quoting Gundlach and Hanke's study:] "Although this is by no means a definitive study of the issue, the strength of the findings is striking. The Tutwiler Prison data suggested that almost one fourth of the African American female killers might not have been in prison for the killing, had their victims received the same transportation and medical care as their Caucasian counterparts."

> The study covered 468 African American murderers at Tutwiler. So that's 113 people who wouldn't have been convicted for homicide if their victims had received the same medical attention as white people. They would have been convicted on lesser charges like aggravated assault. They wouldn't be murderers.

So yes, homicide numbers may be down, but it does not necessarily follow that violence is also down if other factors are not taken into account.