The US Military says they didn't launch it.
NORAD issued a joint statement with Northern Command stating that it wasn't launched by a foreign government, but saying nothing more.
The Pentagon says it "remains a mystery".
So just who the hell launched a missile from 50 km west of Los Angeles and just north of Catalina Island yesterday?
Someone launched something large, that much is apparent from the video shot by the KCBS news helicopter. This was not a Tomahawk cruise missile or anything that small.