Ghost guns are guns that are unregistered and have no serial number – often assembled by hand from readily available parts.
"This is not a uh, a puzzle piece, a puzzle set that you buy from Amazon and put together as a hobby," said Sgt. Ethan Ragsdale, Santa Barbara City Police Department Public Information Officer.
It is a felony to own or manufacture a ghost gun, but despite the guns being illegal, Santa Barbara police are seeing more of them.
"It's a new thing that we're seeing across the country and also here in Santa Barbara as well," Ragsdale said.
San Luis Obispo police say that so far, ghost guns have been rare in San Luis Obispo County.
"A couple months ago we recovered one on an active case that we're investigating, but other than that we don't see them that often," said Lt. John Villanti of SLOPD.
But across the country, they have become popular tools for criminals.
"It's simple, it's inexpensive and it's probably actually cheaper than going to the gun store and buying one," Villanti said.
But new regulations are trying to change that.
On Monday, President Biden announced new restrictions on ghost guns. Manufacturers are required to ensure the pieces used to assemble the gun display a serial number, and sellers of the weapon must now submit to background checks and be licensed.
Ragsdale is hoping the new regulations will make it more difficult to obtain a ghost gun.
"Hopefully, we'll see a decrease in these guns based on this regulation and also a decrease in violence within our country, our state and the community," Ragsdale said.