The Washington Post has updated its total of killings by police officers last year, finding that police shot and killed 998 people, 11 more than in 2017. In 2016, police killed 963 people, and 995 in 2015. Years of controversial shootings, protests, heightened public awareness, police reforms and increased officer training have had little effect on the annual total. Mathematicians say probability theory may offer one explanation. The theory holds that the quantity of rare events in huge populations tends to remain stable absent major changes like a fundamental shift in police culture or extreme restrictions on gun ownership, which are unlikely. “Just as vast numbers of randomly moving molecules, when put together, produce completely predictable behavior in a gas, so do vast numbers of human possibilities, each totally unpredictable in itself, when aggregated, produce an amazing predictability,” said Sir David Spiegelhalter, a statistician at the University of Cambridge.
The ongoing Post project relies on news accounts, social media postings and police reports. The FBI last month launched a system to track all police use-of-force incidents, including fatal shootings. The system is voluntary. The Post’s reporting shows that both the annual number and circumstances of fatal shootings and the overall demographics of the victims have remained constant over four years. The dead: 45 percent white men; 23 percent black men; and 16 percent Hispanic men. Women accounted for about 5 percent of those killed, and people in mental distress 25 percent. About 54 percent of those killed have been armed with guns and 4 percent unarmed. “We’ve looked at this data in so many ways, including whether race, geography, violent crime, gun ownership or police training can explain it, but none of those factors alone can explain how consistent this number appears to be,” said criminologist Geoffrey Alpert of the University of South Carolina.
See “Experts Plan Major Research Project to Reduce Police Shootings” in The Crime Report.