The gunmen in both of the recent shootings in Monterey Park and Half Moon Bay, California, had an unusual profile compared to most perpetrators of violent crime: They were both senior citizens.
The Monterey Park gunman, who killed 11 and injured nine before fatally shooting himself, was 72. The Half Moon Bay gunman, who killed seven people before he was arrested in what police have characterized as an act of workplace violence, is 66.
Mass shooters of that age are rare, especially those with no prior criminal record, as was the case with the Half Moon Bay gunman. (The Monterey Park gunman had one arrest in 1990 for illegal possession of a firearm.) According to data from the National Institute of Justice, mass shooters between 1966 and 2021 were on average 34 years old, and those over the age of 60 accounted for a little over 3 percent of all mass shootings, which are defined as shootings in which four or more people are killed.
The notion that people “age out of crime” is one of the most well-documented phenomena in the field of criminology. The California shootings should be seen as exceptions to that principle, not as nullifying examples, according to Ashley Nellis, co-director of research for the Sentencing Project, which advocates for criminal justice reform.
“The predictability of age is probably the most reliable point of data that we have about people who commit violent crime. Young people are just substantially more likely, and by extension, older people are substantially unlikely, to commit crime,” Nellis said. “It’s certainly a cautionary note to anybody who would be jumping to make policy based on these two events.”
Research has repeatedly shown that criminal activity increases throughout teen years, reaches its highest point at age 17, the oldest that someone can be charged with a juvenile crime, and subsides thereafter throughout life. Property crime peaks at a slightly younger age than violent crime. But even chronic offenders would be statistically likely to stop committing crime by around the age of 40, Nellis said.
There are a lot of theories as to why that might be. Typical milestones associated with getting older, like graduating or getting married, may put people on a trajectory that veers away from criminality. Brain development isn’t complete until the mid-20s, hindering decision-making that might lead to crime and risky behavior. Young people have less financial security, and people in poverty are more likely to commit crimes. Some crimes might be physically demanding, and older people just might not have the strength to carry them out.
But both gunmen in the California shootings buck the archetype of a violent criminal, and their motives still aren’t entirely clear. Investigators have said that the Monterey Park shooter frequented the dance studio where he killed his victims and that the Half Moon Bay gunman, who lived and worked as a forklift driver at a mushroom farm, was angry at the coworkers he shot. Previously, there have been mass shooters as old as 70, including a gunman who opened fire at a church in Vestavia Hills, Alabama, and killed three people last June.
Though age can sometimes factor into the decision to impose a less harsh sentence on young offenders, the Half Moon Bay shooter’s advanced age won’t have any bearing on the length of his sentence, as is standard practice in the US.
He will be charged with seven counts of murder and one count of attempted murder, with a special circumstance allegation of multiple murder and sentencing enhancements for each count because of his use of a firearm, the San Mateo County district attorney announced Wednesday. If convicted on those charges, he could be facing up to life in prison without the possibility of parole. (He won’t face the death penalty, given that California Gov. Gavin Newsom, a Democrat, placed a moratorium on executions in the state in 2019.)
Life sentences without parole have become increasingly common in the US over the last few decades. But Nellis argues the age of older offenders like the Half Moon Bay shooter should be considered a mitigating factor when making sentencing decisions — especially given that the use of executive clemency to release them early has become nonexistent, as she writes in a 2022 report.
“Regardless of age, somebody who does commit an act of violence like this is likely to be rehabilitated, be reformed, be ready to return to society within 10 years,” she said.
Recidivism is unlikely among older people, according to data from the US Sentencing Commission, and keeping them in prison comes at a high taxpayer cost, which includes health care bills that balloon at the end of life. It’s difficult to say how much those who’ll decide the fate of the Half Moon Bay suspect will take that data into account; his initial arraignment is Wednesday.