No criminal record. 

The main thing of course is to be aware of and follow all the additional tenant protection ordinances that seattle has which go a lot further than WA state landlord tenant law does.Seattle has a just cause eviction law ,    additional categories of 'protected class' that you cannot discriminate against,  there are rules around what you can and cannot consider when doing screenings  (you cannot consider most criminal history for example),   and there are rules forcing you for example to accept a six month interest free payment plan for deposit and last months rent if the applicant requests it.   

If you tell them up front that you require a minimum income of 3x the rent, a credit score of at least 650, and that you will conduct a credit/criminal background screening on every adult, that should weed a lot of them out before they bother applying.

People are much more likely to tell you, "We'll think about it...we have a couple more places to look at", than they are to tell you "I have a criminal record/bad credit/eviction record/whatever and don't think we'll qualify for your rental".Of course, if your rentals are overpriced, and they are able to find comparable housing for less money, then that's another possibility as to why they aren't coming back to complete an application.

We got hosed by a criminal turnkey company there in Chicago so that was/is a tough experience.

What is the best site to use for background, eviction, credit, criminal checks? 

@Brett HearnI would lower credit score requirement to around 525 or 550 and up income requirement to 3X rent.Low credit score usually isn’t an issue if they don’t have evictions or criminal record and good landlord references.

The fee is $10K plus criminal chargesAs a whole seller, you'll take a title on yourself, complete POS and then sell it again?

not one or two.and I know others that got criminal charges and ended up in jail as there business model was to get into title never pay on the first and rip the rents until the bank took the home.. 

Here are a few for you:Pros- Online account access- Online payments- Prompt responses to e-mails and voicemails- Good criminal background and credit checks- Actually calling past landlords, employers, etc.Cons- Charging a credit card processing fee- Lack of advertising (e.g. only posting the rental on the company website)- Lack of communication during vacancies (e.g. not providing me with updates on repairs, tenants applications, etc.)- Only using in-house maintenance (e.g. if your one guy can't get to something for a couple weeks then hire a contractor)