The hand-assembled firearms — which are legal for people who are legally allowed to possess other firearms — are effectively untraceable, because the most crucial parts have no serial numbers.
Authorities believe that gangs have begun to build their own homemade guns with parts purchased on the Internet and shipped to California from out of state because it has become more difficult to acquire full-assembled weapons.
Bill McMullan, special agent in charge of ATF’s L.A. Field Division, told the Times, "Criminals are making their own weapons because they cannot buy them legally … or they are paying other people to make those guns for them to get around the gun laws."
Recently, police seized 45 and arrested 10 alleged gang members involved in the manufacture and sale of ghost guns to criminals.