You need some body experienced to help you here.    

Friends had called police, etc and had taken care of the body and the animals... so far, so good.  

In which case the mouse may have just "passed on through"  by now,  is dead in the snow,  you'll find it's little desiccated body after the thaw.

The owner is fully entitled to do whatever they want to their property as long as the appropriate governing bodies say it’s okay.

Is its demeanor calm and relaxed, or does it lock eyes with you, tense its body, and growl?

@Wes Stange not only are the prices in Seattle proper intimidating, but so is the regulatory environment.

(dept of regulatory agencys.) 

The answer is NO.For some reason, through the years, over 30, the body language and reaction to the security amount is a good indicator if the tenant pays on time or not in the future.

Two different bodies, they have different forms.Be sure to memorialize or write down whatever options you end up exercising, They should sign a Termination Agreement with you.

ThiEnsure that any modifications for disability access they make with your permission are reversible and they agree to reverse these modifications at their expense and not leave you your property with rails and other modifications which an able bodied person will not want in their home if you need to find a new tenant in the future and ensure that all reversal of modifications are done in a professional manor and you are not left with silicone preventing windows from closing or anything else for that matter.You should have everything documented and signed by tenant or the legal carer .