It is admirable that you want to help people....however I would not mix your investing with your desire for social justice.  

My husband got to keep it in the divorce (long story) and it was poetic justice when it flooded the year after he "won" it LOLOLOL!  

I read through the ADA, FHAct, HUD and Rehabilitation act as well as reached out to the Department of Justice and numerous local attourneys looking for answers. an "Emotional Support Animal", is not defined in any of those governing documents.

Reality is once you receive the eviction approval from the Justice Of Peace - very few tenants will contest the Eviction further as tenant has to Post One Month rent as a Deposit to proceed, so you would receive the Additional Monies at end of the process. 

Unlike tenant eviction which is handled at the District Justice level and is easy to do yourself without an attorney, Ejectments must be done in the Court of Common Pleas, and while you CAN do it yourself, in almost all cases you will need an attorney.If they are the former owners or a tenant with a lease, then they are not trespassers, and their removal is not a criminal matter but a civil matter that will not be helped by you calling the police or filing a police report. 

Check out Northwest Justice Project : Your Rights as a Tenant in Washington State.

Words really don't do justice to his response.

I think you have to file an eviction at the justice of peace.

mhmm i know i love my RED STATES lol i also remember taking a criminal justice course and spending half the semester on intent and long story short is if you have a book bag full of drugs and you can prove you did not know they were there you CAN BEAT THE CASE... never actually happened as far as i know but basically if you grabbed your roommates bag by accident and they came in took the charge and explained it but i don't know anyone who has a room mate that is that nice lol MY POINT IS WHO CARES... not legal advice but if you accepted 2 applications at an open house at the same time and they both say they think they want to move in but are not sure... than you get positive reports for both perspective tenants and they both email you at the same time saying yea they are 100% sure they want it and will have a deposit the next day....

Then look at local laws as well.If you want some free legal advice, you may try asking the court/Justice of the Peace that handles evictions for your area.Also, you may contact the local BAR Association, and they can usually get you a consultation with an attorney for about $50.