I think you will find that the ticket is in fact legit (you can register and verify its validity HERE if you'd like), that it is not a red light camera ticket nor is it related to the presence of cameras at several intersections in the city of West Hollywood. instead they are issued and mailed pursuant to California Vehicle code section 40202 which states:
40202(d) If, during the issuance of a notice of parking violation, without regard to whether the vehicle was initially attended or unattended, the vehicle is driven away prior to attaching the notice to the vehicle, the issuing officer shall file the notice with the processing agency. The processing agency shall mail, within 15 calendar days of issuance of the notice of parking violation, a copy of the notice of parking violation or transmit an electronic facsimile of the notice to the registered owner.
These citations are not based upon nor do they need to be validated via photographic evidence; instead, the citing officer's statement is sufficient (and typically, the fact that a citation was issued is sufficient proof that a violation occurred in the presence of an officer). And lastly, this is issued as a parking citation, the officer # is sufficient substitute for his signature, in fact, none of the new electronically generated parking citations are signed bu the issuing officer; and as any other parking ticket, these are handled through parking enforcement (although if you do decide to appeal it, the third level of the appeals process will be handled by a judge in the superior court having jurisdiction over that area).
If you weren't there at that time, is it possible that someone else was driving your car? Either way, and with you (presumably) being the registered owner of the vehicle, any citation issued by parking enforcement would be issued in your name anyways.
So, first thing you should check to see if they in fact did issue and mail the citation within 15 days of the date it was issued.
Fortunately for you, you aren't alone... By my count, we have had five or six people post about having received a similar citation.. Some with, others without a photograph. Admittedly, I had a slow start in that thread, and while there are no definitive answers as of yet, we are in fact awaiting an update from the original posted who started that thread. And rather than rehash everything that was discussed there, you will find it here: West Hollywood Red Light Camera Gridlock Ticket.