Instant Background Checks for Gun Purchases – What is Checked and Who Populates the Databases?

by James C. Sherlock

The FBI National Instant Criminal Background Check System (NICS) is much discussed and little understood by the general public.

In an effort to help, this article will inform readers about the NICS Indices, what information is kept there and how it gets there. The information here about the NICS is quoted or adapted from the FBI descriptions of the system it runs.

Then we will look at Virginia background checks specifically.

You will find that the utility of the data used for such checks, and thus who is sold or is not sold a gun by a licensed dealer, varies a lot.

It depends to a great degree upon the prosecutorial philosophy and policies of the Commonwealth’s Attorney where the buyer was raised and has lived since reaching adulthood.

What is the NICS? Broadly, the NICS Indices contains information on people who are prohibited from receiving firearms by federal or state law. This information helps the FBI, and the State Police in the case of Virginia, make sure firearms are not sold or transferred to people who are prohibited from receiving them.

From what sources are data input into the NICS Indices? The NICS Indices contain information provided by federal, state, local, and tribal agencies on persons prohibited from receiving firearms under federal or state law.

If the information is available in the National Crime Information Center (NCIC) or the Interstate Identification Index (III), entry into the NICS Indices is not always necessary; therefore, certain categories within the NICS Indices may show minimal or no participation by a federal or state agency.

What are the data categories in the NICS Indices? NICS Indices Categories and Participation:

  1. Felony—the number of entries in this category might be low or nonexistent, because the best location for the information is III. A NICS Indices entry would be ideal if the felony conviction information is not available in III.
  2. Under Indictment/Information—the number of entries in this category might be low or nonexistent because this information may be found in III.
  3. Fugitive from Justice—the number of entries in this category might be low or nonexistent because, ideally, warrants are contained in NCIC.
  4. Unlawful User/Addicted to a Controlled Substance—this information may be found in III; however, if a qualifying conviction does not exist, but the prohibition has been established, the NICS Indices is an alternative.
  5. Adjudicated Mental Health—since most information for this prohibition is not available in III, there is the expectation for the number of entries in this category to be elevated.
  6. Illegal/Unlawful Alien—the U.S. Immigration and Customs Enforcement (ICE) makes the majority of the entries and Customs and Border Protection (CBP) most of the rest; therefore, the number of entries in this category by other federal agencies or the states should be low or nonexistent.
  7. Dishonorable Discharge—the U.S. Department of Defense (DoD) makes entries; therefore, the number of entries in this category by other federal agencies or the states should be low or nonexistent.
  8. Renounced U.S. Citizenship—the U.S. Department of State (DOS) makes entries; therefore, the number of entries in this category by other federal agencies or the states should be low or nonexistent.
  9. Protection/Restraining Order for Domestic Violence—the number of entries in this category might be low or nonexistent because protection order information ideally is contained in NCIC.
  10. Misdemeanor Crimes of Domestic Violence (MCDV)—this information may be found in III; however, if the information is unable to be updated to III, the NICS Indices is an alternative.
  11. State Prohibitor or Court-Ordered Firearm Restriction—these prohibitors include individuals who are prohibited based on state law or court-ordered firearm restriction only. This category is unique to each state/territory and dependent upon state law. (Some emphasis added).

Virginia. The Virginia State Police enter data into the Virginia Criminal Information Network (VCIN) that is linked to the NCIC.

So why does Virginia have the state police run the checks using access to NICS rather than the FBI doing it directly as in 31 other states and D.C.?

  • One reason is that Virginia has its own law listing disqualifications for gun purchases that may not match in every respect federal laws.
  • Another may be that Virginia is a one-gun-a-month state, so the Virginia State Police check records for prior purchases.

For selected other Virginia laws pertaining to firearms see here.

Problems? So that is what is checked, where does it come from and who runs the checks in Virginia.

Are there problems at the input level? Absolutely, but read again the disclaimer above about sources. There are multiple federal and state databases that are automatically absorbed into the NICS, and multiple Virginia databases absorbed into the VCIN and available in the NICS.

Pundits. I have read progressive-authored opinion pieces that berate some states for not directly entering certain data into NICS. That is turned into a charge that the background check data are worthless.


There will always be errors and gaps in data entered by human beings, but the databases are astonishingly complete within the categories instantly searched. They have supported their intended use. The FBI reports

Since launching in 1998, more than 300 million checks have been done, leading to more than 1.5 million denials.

You will see in the linked Active Records in the NICS Indices As of December 31, 2021 that some states directly enter data into the NICS that they need not because it is in the NCIC or the III. Other states let those data transfer automatically into the NICS and do not make double entries, which can cause data quality issues.

Montana, to pick one state, does not enter anything but adjudicated mental health data directly into NICS. If you look at the data fields, you will see that is the only category that every state must enter there. The rest can enter the NICS from other databases.

Pundits may look at the spreadsheets and not those caveats highlighted above. Or they may not care to mention them when composing a rant. Or whatever.

While you are looking at the document, you can check out Virginia’s direct (active) inputs.

What could go wrong in Virginia? I am very much in favor of requiring background checks for every transfer of a weapon in Virginia, not just those purchased through a Federal Firearms Licensee (FFL) as now.

Perhaps the biggest issue in Virginia about our entries into the background check data is that:

  • a person must at least be indicted in the criminal justice system or adjudicated in the mental health system to be turned away from a gun purchase.
  • Some jurisdictions are much more likely to indict that others for the same offenses. Felonies pled down to misdemeanors don’t show up.
  • Domestic violence offenses pled to something else also do not show up.

So, much of the utility of the background check is at the discretion of your local Commonwealth Attorney.

I therefore dedicate this to social justice warriors recently occupying some of the 120 Commonwealth Attorney jobs in Virginia:

  • Hon. Amy Ashworth, Prince William County and City of Manassas
  • Hon. Anton Bell, City of Hampton
  • Hon. Buta Biberaj, Loudoun County
  • Hon. Parisa Dehghani-Tafti, Arlington County and City of Falls Church
  • Hon. Steve Descano, Fairfax County and City of Fairfax
  • Hon. James M. Hingeley, Albemarle County
  • Hon. Stephanie N. Morales, City of Portsmouth
  • Hon. Joseph D. Platania, City of Charlottesville
  • Hon. Bryan Porter, City of Alexandria
  • Hon. Shannon L. Taylor, Henrico County

I hope this information proves of use.