California is adding a secretive but growing class of weapons to those that can legally be seized under gun violence restraining orders, under a bill Gov. Gavin Newsom signed into law Friday.

What also is known as a “red flag” law allows police along with family members, colleagues, employers and teachers to ask judges to take firearms from those they fear are a possible threat to themselves or others.

The new law includes what are known as “ghost guns” in the definition of what may be seized starting July 1, 2022. They are guns assembled from parts and so might not be registered or purchased through a dealer, as are other firearms that are legally owned.

The same expanded definition also applies to domestic violence restraining orders.

Assemblywoman Cottie Petrie-Norris said her bill closes a loophole in the law by ensuring “that these readily available weapons which look and act like any other firearm are treated appropriately.”

The ghost gun kits or parts can’t be seized under current law, according to gun violence prevention advocates the Brady Campaign, even though the unfinished or unassembled parts can readily be turned into a working weapon. Unlike traditional guns, the unfinished parts can be purchased without background checks or waiting periods.

There was no listed opposition to the measure, which passed all legislative hurdles without a dissenting vote.

They were among seven related measures that Newsom signed into law.

He said the action “strengthens enforcement of our common-sense gun safety laws, helping ensure that dangerous individuals who are prohibited from possessing firearms surrender their weapons and advancing other lifesaving polices to make our communities safer.”

A related bill allows those seeking domestic violence and gun violence restraining orders to file electronically and appear remotely at hearings where judges decide whether to grant the orders.