SAN FRANCISCO (AP) — San Francisco's district attorney says he's suing three California companies that make and distribute “ghost guns,” the untraceable, build-it-yourself weaponry that accounted for nearly half the firearms recovered in San Francisco gun killings last year.

The suit alleges the companies violated state laws that require them to apply for serial numbers and that they misled consumers into believing the weapons were legal.

The suit comes as opponents are pursuing a recall campaign against the district attorney over his handling of crime.

Critics say he is intolerably lenient, while supporters say he's following through on promises to reform systemic inequities in criminal justice.