California Attorney General Rob Bonta has released a report indicating that firearm microstamping technology is viable. The technology involves imprinting a unique microscopic array of characters, known as a microstamp, on spent cartridge cases from firearms equipped with microstamped firing pins. This report follows amendments to the Unsafe Handgun Act requiring new semiautomatic pistols to have microstamping capabilities for law enforcement tracing purposes.
The California Department of Justice’s investigation found that semiautomatic pistols with microstamping components regularly produce legible microstamps on spent cartridge cases, even after repeated firing. The investigation was conducted by the DOJ’s Bureau of Forensic Services in consultation with legal and subject matter experts, including input from stakeholders.
“My office’s investigation into the technological viability of microstamping components has found that this technology is viable,” said Attorney General Bonta. “Microstamping technology could help law enforcement match cartridges found at crime scenes directly to the firearms they came from. Today, my office released a report outlining the findings of our investigation in an effort to provide appropriate transparency as to the basis of our determination.”
In 2023, Governor Gavin Newsom signed Senate Bill 452, authored by Senator Catherine Blakespear (D-Encinitas), amending California’s Unsafe Handgun Act and adding new requirements for microstamping components in semiautomatic pistols sold or transferred in the state. Starting January 1, 2028, all semiautomatic handguns sold by licensed dealers must be verified as microstamping enabled.
The DOJ report outlines findings such as engraved firing pins consistently leaving legible microstamps on spent cartridge cases and reliable data imprinting across various firearms and ammunition types. Even incomplete microstamps can provide useful leads for solving gun crimes.
This fall, DOJ plans to provide written guidance on performance standards for producing microstamping components. Early next year, applications for licensure will be accepted from entities producing these components meeting performance standards.
A full copy of the report is available online.
