The Washington trespass statute specifies: “In any prosecution under RCW 9A.52.070 and 9A.52.080, it is a defense that: (1) A building involved in an offense under RCW 9A.52.070 was abandoned; …”The other links to Cornell University web pages that you provided about Real Property or Adverse Possession do not discuss nor even use the words abandon or abandoned.

@So Da  He doesn't need a reason, the lease is up, he is not renewing.And for those who think all those jobs signs you see are hiring they are not. 

Na, we're going to keep it. 

There's too many factors to tell you off a web forum, but you should be able to figure this out quickly looking around zillow or apartments.com.

He mentions he can find out of state properties from auction web sites for cheap around 10k.

My specialty is in the IRA arena not web marketing. 

If you're not doing ACH and only have a few units, the web-based software is free to use.  

Aly NA I like the idea of asking the landlord how they know the person.

NA Onyido - Yea, check it out!

Make sure when you are evaluating custodians they have an interactive web site with a chat function so you can get answers right away.