Upon delivery of the note, anyone in the house, above 18-y-o who is served would suffice the pre requisite to continue an eviction.  

We absolutely support persons with disabilities, however as seen on TV, folks taking advantage of the system are not far from your doorstep.

Sorry you're dealing with it.Oh, and send the letter with proof of delivery (USPS priority mail letter with proof of delivery is perfect - they don't have to sign for it, and you have proof she got it).Also, make sure you give the proper amount of notice to not renew the lease - in CA if they've been in the unit over a year it's 60 days - just check and do it right.

I'm sure you've tried your best to keep them moving so keep that going and if they stall, serve them their 3 day notice to vacate in their hand, document delivery and then see if that lights a fire under them.  

I liked using priority mail with delivery confirmation, when necessary to have official notice of anything. 

Doesn't cost much for the notice and delivery/posting.  

Cut a deal that you will source with one if they take care of you and handle all the delivery/warranty matters.Many tenants want the service of them so you will rent quicker if you provide the option.  

Something has changed in USPS First Class mail delivery.

(pray that you don't find the body).If Mom had called you on the 14th when she was clearing out the property and gave you ALL the keys I'd be more apt to go along with the STORY but here you are sitting by the mailbox waiting for a delivery from someone that hasn't acted in your favor for over three weeks. 

If you don't have a new address from him, mail it with delivery confirmation to the rental address (his last know address).If he still owes you money after that, then I recently found this collection agency, which I've never used, but in your shoes I would try them out.