The police share of violent deaths in the late 1960s was low in part because a lot of Americans were dying in Vietnam. That share spiked afterwards, but then fell again as murder rates exploded. But since 1992, the police have accounted for an increasing share of all violent deaths in America. The pace of increase has been especially dramatic since 2002. This calculation shows the frequency of police killings has risen by much more than criminal or terrorist violence, which suggests that rising police violence is probably not a response to rising criminal violence.

There’s another way to check and see if criminals have gotten more violent, too. Since 1994, the FBI has collected statistics on law enforcement officers killed in action (LEOKA). Again, reporting of the data is inconsistent and requires adjustments. But what data do exist suggest that killings of police officers have actually declined over time, both in raw and reporting-adjusted terms…

There are still other reasons to suspect that the rise in police killings is driven by the police becoming more violent in general, not by justifiable killings. One simple reason is that “justified homicides” reported to the FBI have not risen by much (shown in Figure 1), even though other sources show an increase in police killings. It stands to reason that a lot of the killings departments don’t report as justified homicides are, in fact, not justified homicides…

To summarize: police killings have risen despite no increase in social or criminal violence generally. Police killings have risen despite a decline in actual killings of police officers (and, as related data show, a decline in assaults of police officers, too). Police killings have risen, but this rise is not driven by reported officially justified homicides, nor is it associated with a larger share of police killings involving armed victims. Instead, what we’ve seen is a rise in police killings across the board, untethered from actual threats to society, with the victims often being unarmed innocents. About 15 to 25 percent of police killings are of unarmed people.