"When There's an Unarmed Person Coming at Them with a Knife or Something, You Shoot Them in the Leg"

Advice from Vice-President Biden.

From Yahoo News (David Knowles):

"Instead of standing there and teaching a cop, when there's an unarmed person coming at them with a knife or something, you shoot them in the leg instead of in the heart is a very different thing. There's a lot of different things that could change," Biden said in a meeting with community leaders at Bethel AME Church in Wilmington, Del.

I don't fault Biden much for the "unarmed person coming at them with a knife" slip—that happens in oral remarks—but I think his broader advice doesn't make sense. Most studies suggest that most police officers, even with substantial training, miss with 50-75% of their shots; here, for instance, is the RAND report on the NYPD:

As has been reported nationally, police officers often miss their targets (Morrison,
2006, p. 332). The NYPD reports hit-rate statistics both for officers involved in
a gunfight and for officers who shoot at subjects who do not return fire. Between
1998 and 2006, the average hit rate was 18 percent for gunfights. Between 1998
and 2006, the average hit rate in situations in which fire was not returned was
30 percent. In 2006, the hit rate against subjects who did not return fire was 27
percent.

The LAPD reported a hit rate of 48% in 2016, 38% in 2015, 34% in 2014, 20% in 2013, and 27% in 2012; I suspect that the 48% is at least as much random variation as real improvement. Politifact reports similarly low numbers from other studies (with a couple of highly questionable 1991 100%s in San Antonio and San Francisco, and an outlier 56% in 1970s L.A.).

And this isn't surprising; most police officers have never fired a gun in a combat situation. When someone is charging at you with any weapon, and the adrenaline is pumping, you're not going to be a cool sniper-level shooter, especially if this has never happened to you before. Going to the range will only do so much to improve your performance in such situations.

Now imagine what would happen if police officers shifted from how they're trained to shoot—for the center of mass in the torso, where if you miss your specific target you still have a good chance of hitting some part of the attacker's body—to shooting at the leg. Not going to turn out well, I think; fewer hits on the attacker, more dead police officers, and probably more bullets hitting bystanders, where there are bystanders present.

Police officers shouldn't shoot at all at people who aren't really posing a serious threat to them or to others. But if they reasonably fear death or serious injury—and a "person coming at them with a knife" would surely qualify—they should shoot in the way that's most likely to hit and stop their attacker. And that's in the torso, not the leg.

Obligatory citation: Vice-President Biden's previous gun advice.