As a proeprty owner in CA The procedure it not hard and is described well by @David G.

Even so, if the son doesn't communicate with you about the matter, you may need to proceed with abandonment procedures.

I suggest following the letter of the law and create a written policy, procedure and checklist for dealing with eviction timelines and tenants possessions consistent with local judges' interpretation of the law. 

Also, there are also a lot of young Doctors ( read medical/dental residents) who often move out of state  just for the duration of their residency.

Whatever your policies and procedures are you need to stick with them.

Think through scenarios and set up a procedure manual to guide you.  

Most likely you will need to follow the legal procedure outlined for abandonment.

Since I didn't place the first one so I'm not stressing that one, but the second one is a result of me deviating 1/2 an inch from my standard procedure.  

You can toss out what's obvious garbage, and they suggest you store anything that looks like it's of value for a reasonable time, and send the tenant info to come get their stuff by X date.http://www.nolo.com/legal-encyclopedia/handling-te...It looks like different cities and counties in Ohio have different court websites, and without looking closely, it looks possible the procedures may be different depending on where you are, so Google your city or county and "housing court evictions"This one for Cleveland says you need to first serve a 3 day notice to pay or quit, wait 3 business days, then start the eviction through Housing Court.http://clevelandhousingcourt.org/hc_fq_b.html

Accepting cash is a big and risky effort, as there are so many ways an error can occur, through process and procedure, and all caused by the mere fact that cash is involved.