It happened too quickly for me to notice what the lead car was, though it wasn't going terribly fast (maybe 40-45 MPH... I'm on a small side street). But it was immediately followed by at least eight cop cars—I counted!—all with their sirens blaring, and two or three helicopters, and it blew through the stop sign at the end of my block and then the next few blocks before I couldn't see it anymore, though judging from the helicopters it turned east on Wilshire headed towards downtown (I'm in Koreatown).
Suddenly I feel like a real Angelino! Well, that and ridiculous about how excited it made me. But, a real old-fashioned car chase! Out my window!