20 days since I got back from my last trip and this insect is just sitting on my carpet tonight. Seems to be a harlequin cockroach. harlequin pic about half way down

Pic about 40% down

I've found websites saying these are found in Mexico and Arizona, but they're not really in California. A University of California Riverside website mentions "...In California, a single adult was found in a warehouse in Los Angeles in 1958, and another in a box of tomatoes in a market in Santa Rosa in 1965. An adult was found on a tomato fruit in a field near Watsonville in 1966. This species was occasionally found on Travis Air Force Base, California, where cargo planes were arriving from Vietnam during the war..."

I live 2 blocks from the ocean and the weather has been in the 40's and 50's (5 to 12 celcius) during the night. The weather is overall drier and colder than Mexico and Southeast Asia, so I don't think this guy came in from outside.

Could this be a stowaway from my luggage? Could it have been very small and is now big?

Ok, the girlfriend confirmed that these are very common back home in Chaiyaphum where we visited for 4 days. I'm mildly horrified that this thing stayed put for the few days in Bangkok, and then rode the whole way back. Then it camped out somewhere for 3 weeks before I spotted it.

I feel like I have to fumigate my luggage from now on so nothing nasty gets loose.