A criminal background check is not one search. It is a set of searches run in different places by different methods, and the difference between a cheap one and a thorough one is which of them you paid for. This page separates them, in the order a provider actually runs them, so you can tell what an entry package is giving you and what it is quietly leaving out.
The searches, and what each one is worth
A trace on the applicant's Social Security number establishes identity and prior addresses, which is the map for everything after it. A national criminal database sweep is fast and broad but assembled commercially from uneven sources. County criminal court searches go to the court that actually holds the record, and in most of the United States that is where a conviction lives. Federal district court searches cover federal offences, which the county courts do not hold at all. A sex offender registry search runs against the public registries. Each of those is a separate line, and a package priced at the market floor typically includes the trace, the database, the registry and one county.
Why the database is a lead and not an answer
The national criminal database is a private aggregation, not a federal index. Coverage varies by state and by county, update cycles vary, and expunged or sealed records occasionally persist in it after they should have gone. A provider that reports a database hit straight to you is handing you information the FCRA expects to have been checked, because the statute requires reasonable procedures to assure maximum possible accuracy when a report is prepared for employment. The right practice, and the one better providers follow, is to treat a hit as a pointer and confirm it at the originating court before it appears on your report.
Basic, name based and comprehensive, in plain terms
A basic background check usually means the trace, the national database and the registry, with no live court search at all. A name based background check is any search run against a name and date of birth rather than fingerprints, which is what almost all commercial screening is. A comprehensive background check normally adds several county searches across the address history, federal district courts, and often verifications on top. The words are marketing rather than legal terms, so the only reliable question to a provider is which searches are in the package, not what tier it is called.
The civil side, which is a different record entirely
A civil background check searches civil court records: judgments, liens, evictions and civil litigation, rather than criminal charges. It is a different index in the same courthouses and it is bought separately. Employers ask for it far less often than they think they should, and where it does matter is roles with fiduciary or property responsibility. Bear in mind that some civil items are subject to the FCRA's reporting time limits in a way convictions are not.
Questions people ask about criminal background check
Is a national criminal database check enough on its own?
No. It is a commercially assembled aggregation with uneven coverage and update cycles. Treat a hit as a lead to be confirmed at the originating court, and treat a clear result as weak evidence rather than proof that nothing exists.
What is the difference between a county and a federal search?
They are separate court systems holding different offences. County courts hold most convictions in the United States; federal district courts hold federal offences such as wire fraud or drug trafficking prosecuted federally. Searching one never returns the other.
Does a criminal background check show arrests that did not lead to conviction?
Sometimes, and it is heavily restricted. The FCRA bars reporting most non-conviction adverse information older than seven years, several states bar reporting non-conviction arrests at all, and EEOC guidance is that an arrest without a conviction does not by itself establish that conduct occurred.
How many counties should I search?
Enough to cover where the applicant has actually lived during your lookback period, which the identity trace tells you. Searching one county for a candidate who has lived in four is the most common way a thorough-looking check misses everything.