There are approximately 4500 species of cockroaches in the world. In Sacramento the most common are: German, Oriental, American, and the new kid on the block... The Turkestan roach (Blatta lateralis).
What is really interesting is just how quickly the Turkestan roach has taken over California. Just a few years ago you would see Oriental and American roaches but now its 99% Turkestan roaches. Turkestan roaches are outdoor roaches. That means that they typically live in the sewers, organic waste (leaves), irrigation boxes and other high moisture areas. They are typically content to live their lives outdoors. When they do come inside, its almost always the garage or bathroom... but they can fully infest a home if given the right living conditions.
What has really been strange is just how many I've seen this year. I've lost count of how many times a client who have never seen a roach in their life suddenly have Turkestan roaches in their yard and home.
They don't look like typical cockroaches (especially the female). The male is on the right, female on the left in the photo above.