SACRAMENTO, Calif. (AP) — California could expand its unique law requiring individual identifiers on all bullet casings to include weapons used by law enforcement.

Proponents say the pending legislation is another attempt to help investigate shootings by police while jumpstarting what the gun industry says still is unworkable technology.

The state’s long-delayed law requires gun manufacturers to adopt microstamping technology on new types of handguns introduced in California. That is aimed at imprinting a unique set of microscopic characters on all cartridge casings when weapons are fired.

That would link bullet casings left behind by semi-automatic weapons to the guns that discharged them.