Thank you for your report! You are correct, that is 3-lined cockroach, the recent invader, rather than the more common German cockroach. Luckily, the 3-lined cockroach is a nuisance pest that may come indoors at the end of summer, whereas German cockroach is a major public health hazard and very difficult to exterminate. Here is a fact sheet from UC: you may not need to take any control measures at all if numbers are low.
https://ucanr.edu/blog/pests-urban-landscape/article/three-lined-cockroach-introduced-nuisance-pest-california

Tom Valente
Sept. 22, 2025, 10:55 a.m.