This used to be a very straightforward question because there were only two actual sources of official criminal records: the state patrol and the FBI. In fact, that has not changed. What has changed is the ease with which such records can be found..
Now, post-911 and in the internet age, that question is far more complicated. To begin with, far more employers, schools, sports teams, nonprofit organizations, clubs, and private concerns check criminal records. In our nervous times, we worry a lot more about terrorism, child molesters, thieves, and so on. So one natural response to this worry is to check out every job applicant's, prospective coach's, and volunteer's background--i.e., their criminal record, for starters. And the internet makes it easy..
Just google 'criminal records' and you get various sites such as: criminal.com. Type in a name and you could find out for free if there are records, and then get them--for a fee. The problem is that this site(like many others) may or may not reveal exactly what database it used to give you the information. And not all databases are created equal. For example, let's take court records. Virtually all criminal court records are open to viewing. They are publicly available and free to look at if you go to the originating courthouse. Before the internet, that took a bit of legwork and time. Now many court records are available on line..
Many of the criminal records search engines use court records. So what's wrong with court records as a database for research on someone's criminal record? The problem is that court records include everyone who has ever been accused of a crime, whether the case was dismissed at arraignment by the prosecutor, or later by a judge, or if a jury found the accused innocent. That is, it includes many people WHO DO NOT HAVE CRIMINAL RECORDS! So unless these search engines are actually reading the entire file to make sure, their reports are suspect..
For a criminal record should mean that the person was found or pled guilty, and was convicted and sentenced. So employers or groups who use anything but official sites, such as https://watch.wsp.wa.gov/ in Washington state, are relying on something other than official criminal records. That means anything else may be unreliable..
I have a former client whose case I got dismissed at a pretrial hearing by the judge on the prosecutor's motion. Sometime after this, he submitted a bid for a contract on a job. He was declined. The group that declined his bid told him he had a criminal record and so that disqualified him. He asked what record and they cited the very case we got dismissed. I told him that was not a 'criminal record,' but a court record..
This violated one of the precepts of our legal system: presumed innocent until guilt is proven beyond a reasonable doubt. Maybe he will sue them. Unfortunately, the damage has been done..