Anyone can search anyone's legal history for any reason. Sometimes records may be sealed, if there was expungement or it was a juvenile adjudication, but there is nothing illegal about the search, even in those cases (it's just that you won't turn up anything in the record is sealed). If you are willing to spend the money, hire an investigator to search for you--they know how to search criminal records. Otherwise, start with Google/internet searches; then, if you learn of potential criminal cases, you can search cases filings for those courts and/or send OPRA requests to the police or sheriff's, etc. departments involved.