Could be civil and/or criminal depending on the transaction.

Its mainly to get a criminal background and eviction record.

Unless otherwise provided by law, proof of violations shall not require criminal conviction, but shall be by the preponderance of the evidence."

These days, state laws hold landlord responsible for renting to sex offenders and criminals, and I'm not sure how my insurance company would handle it if one of your subtenants, a known child molester, molested a neighbor's kid.

You or your attorney can file private criminal complaints or whatever, but dollars to donuts, that money is gone.Remember, you cannot collect a judgement against someone who has no income and owns nothing. 

Basically if you have ever been evicted I will not rent to you (assuming I find out which we do a credit and criminal screening). 

I had the parent fill out a rental application so I could run his credit.I also paid a few dollars extra to check his criminal record (the apartment association in that area does both my credit and criminal checks for me).

RCW 9A.52.090    (Revised Code of Washington)Criminal trespass—Defenses.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; or(2) The premises were at the time open to members of the public An owner may, through words or actions, express or imply that he/she no longer has interest in the property. 

the Napa valley and city of Napa has taken some really strong stances to the point of bringing criminal charges.

All the criminal activity in that neighborhood in the past 6 months consisted of larceny/burglary, with most of it not being on Ursula Avenue.