The lack of registration of 'Assault weapons' is somewhat of a 'gating factor' and exposes one to punishment, which might be avoided if the weapons had been properly registered when that was possible.
The crimes are in Penal Code 30600
30600. (a) Any person who, within this state,
manufactures or causes to be manufactured,
distributes, transports, or imports into the state,
keeps for sale, or offers or exposes for sale, or
who gives or lends any assault weapon or any .50 BMG rifle,
except as provided by this chapter,
is guilty of a felony, and upon conviction
shall be punished by imprisonment pursuant to subdivision (h) of
Section 1170 for four, six, or eight years.
and PC 30605 for possession
30605. (a) Any person who, within this state, possesses any assault
weapon, except as provided in this chapter, shall be punished by
imprisonment in a county jail for a period not exceeding one year, or
by imprisonment pursuant to subdivision (h) of Section 1170.
It would appear that Smith might reasonably be charged with violating 30600 for importing, and 30605 for possession.