That's important because entering and preventing the for.mer owner from being able to return is often referred to as forcible detainer. 

THE CA ASSEMBLY WILL VOTE BY MAY 31, 2018 Assembly Bill 2343 (Chiu) rewards tenants who fail to pay their rent or who remain in wrongful possession of a rental unit by delaying the unlawful detainer (UD) process by a minimum of three weeks.

I serve the five day notice, and in my area, the court date for the forcible detainer is usually before the end of the month.  

Just file a normal eviction (Unlawful Detainer) using a company making evictions their business.

Meanwhile you can keep learning, networking and detaining your best course of action.

No thank you.In addition to using the internet search, I use a tool from our local rental association... a list of "Unlawful Detainers" from our county that covers seven years.

If he doesn't respond, file for unlawful detainer (or the equivalent for your jurisdiction).

If they don't leave after the 3-day notice, you will be forced to take the tenant to court and file an unlawful detainer.

If you do not pay the amount owed no later than XXXX, I will file a Forcible Entry and Detainer.

If they don’t you will need to filed for a FED (forced entry detainer) and the sheriff will forcibly remove them if needed.