The killing of 18 people in California just two days apart — 11 in Monterey Park and seven in Half Moon Bay — are the latest horrors in America’s long history of gun violence. But there is a factor in these mass shootings, and with the suspects, that stands out.
The median age of mass shooters in the United States is 32. Yet the man who shot dead 11 people in Monterey Park on Saturday before turning the gun on himself was 72 years old — the oldest mass shooter in modern American history, our records show. Meanwhile, the man who is alleged to have killed seven in Half Moon Bay on Monday was also older than most — 66, the third-oldest in history.
As criminologists, we have built a database of 191 mass shooters using public data. The shooters in our records date back to 1966 and are coded on nearly 200 different variables, including age at the time of attack. Our research shows that mass shootings — defined here as events in which four or more people are killed in a public place with no underlying criminal activity — have become more frequent, and deadly, over time.
