Aaron Chalfin

University of Pennsylvania Website

Aaron Chalfin is an Associate Professor of Criminology at the University of Pennsylvania. He holds a Ph.D. in Public Policy from the University of California, Berkeley.

Voting History

Mass violence

Red flag laws, allowing police or family members to petition a court to temporarily remove firearms from a person who presents a danger to themselves or others, would reduce the frequency or severity of mass violence.

Vote Confidence
Agree 2
Median Survey Vote Median Survey Confidence
Agree 7
Comments

In a country with several hundred million guns, red flag laws are a critical tool as they address risks posed by people who have access to existing weapons. It seems likely that some killings could have been avoided with proactive actions taken by family members/police and laws that support those actions. That said, there isn't much high quality evidence on the effects of these laws.

Universal background checks, which would require almost all firearm sales in the US to go through the National Instant Criminal Background Check System, would reduce the frequency or severity of mass violence.

Vote Confidence
Disagree 5
Median Survey Vote Median Survey Confidence
Agree 5
Comments

Most firearms used in mass killings were purchased legally so there is potentially some promise in more extensive regulation of gun sales. That said, while there are notable exceptions (e.g., private sales), most gun sales in the US are already subject to a background check. Typically the future mass shooter was legally permitted to purchase the weapon in question. Most of the evidence does not suggest that gun shows and the like lead to an immediate change in homicides.

Increasing the presence of armed security at schools and other public venues would reduce the frequency or severity of mass violence.

Vote Confidence
Neutral/No Opinion 1
Median Survey Vote Median Survey Confidence
Neutral/No Opinion 5
Comments

If you have a SWAT team at every significant public venue in the US, this seems likely to reduce the number of killings. But the costs of doing so would likely be prohibitive. My sense is having a police officer at every school might reduce the deadliness of mass shootings if the officer is able to engage the shooter more quickly. But this is an open question and there's not a lot of strong evidence since mass shootings, while concerning, remain rare.