A national criminal database is a searchable repository of criminal history records pulled from jurisdictions across the United States. The largest is the FBI’s National Crime Information Center, which held more than 19.3 million active records as of fiscal year 2025.1FBI. CJIS Division 2025 Year in Review No single system captures every criminal record in the country. The federal government runs several overlapping databases for law enforcement and firearms screening, and private companies build their own by aggregating public court records from thousands of counties. What turns up in a search depends entirely on which database is being queried and how it was built.
The National Crime Information Center
The National Crime Information Center, or NCIC, is the primary federal criminal database in the United States. It’s operated by the FBI’s Criminal Justice Information Services Division under 28 U.S.C. § 534, which directs the Attorney General to collect, classify, and preserve criminal identification records and share them with authorized officials at every level of government.2Office of the Law Revision Counsel. 28 USC 534 – Acquisition, Preservation, and Exchange of Identification Records and Information It runs 24 hours a day, letting officers pull records in seconds during traffic stops, investigations, and bookings.
NCIC is organized into distinct files, each with its own purpose. The wanted person file flags people with outstanding arrest warrants. The missing person file tracks adults and children reported missing. Separate files cover stolen vehicles, firearms, boats, license plates, securities, and other property. There are also files for protection orders in domestic violence and stalking cases, violent criminal gangs, terrorist screening, and identity theft.
Built into NCIC is the Interstate Identification Index, a cooperative federal-state system for exchanging criminal history records. When someone is arrested and fingerprinted, that record goes to the state identification bureau and then to the FBI. If an officer in one state queries a person’s name or fingerprints, the Index routes the request to whichever state holds the underlying record. That routing is what makes NCIC genuinely national rather than just a federal file cabinet.
The National Instant Criminal Background Check System
NICS is a separate FBI-run database designed specifically for firearms purchases. When someone tries to buy a gun from a licensed dealer, the dealer contacts NICS and the system checks whether the buyer falls into a prohibited category.3FBI. Firearms Checks (NICS) Federal law bars certain people from receiving firearms, including anyone convicted of a crime punishable by more than a year in prison, fugitives from justice, people subject to certain restraining orders, and those involuntarily committed to a mental health facility.4Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
The FBI handles NICS checks directly for dealers in 31 states, five U.S. territories, and the District of Columbia. Another 15 states run their own checks through the NICS system.3FBI. Firearms Checks (NICS) In fiscal year 2025, the system processed more than 27 million transactions.1FBI. CJIS Division 2025 Year in Review If the check comes back clean, the dealer gets a unique identification number and the sale proceeds. If NICS flags a potential disqualifier, the sale is delayed while FBI examiners investigate. A dealer may complete the transfer if three business days pass without a denial, though buyers under 21 face a longer waiting period under enhanced review rules.4Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
Private “National” Criminal Databases
When an employer, landlord, or volunteer organization runs a “national criminal background check,” they’re not searching NCIC. They’re searching a commercial database. Private background check companies build these by purchasing or collecting public court records from counties, states, and federal courts. The results are often marketed as national, but they’re really patchwork quilts stitched together from whatever jurisdictions the company has sourced. No private company has direct access to NCIC or any official federal criminal database.
Two weaknesses are worth understanding. The first is coverage. Smaller rural counties sometimes don’t digitize their records or don’t make them available to commercial aggregators, which leaves genuine blind spots on the map. The second is refresh rate. Law enforcement databases update in real time as arrests and warrants are entered. Private databases rely on periodic bulk purchases from court clerks, which might happen monthly, quarterly, or less often depending on the county. A person arrested last week might not appear in a commercial database search for months.
Name-Based vs. Fingerprint-Based Searches
Private databases almost always rely on name-based searches, matching people by name, date of birth, and Social Security number. This creates two kinds of errors. A common name can pull in records belonging to someone else entirely. And slight variations in how a name was recorded, like a misspelled first name or a maiden name, can cause real records to slip through undetected.
Fingerprint-based searches tie results to a unique biometric identifier and are far more reliable. They’re the standard for law enforcement queries through NCIC and for regulated industries like healthcare, education, and childcare where federal or state law requires higher-level screening. Live Scan technology, which captures prints electronically rather than with ink, often returns results within hours. The tradeoff is that fingerprint checks require the person to appear in person at a scanning site, and processing fees vary by state.
Who Can Access a National Criminal Database
The idea that only police can search national criminal databases is an oversimplification. The statute behind NCIC authorizes access for “authorized officials” of federal, state, tribal, and city governments, along with certain institutions.2Office of the Law Revision Counsel. 28 USC 534 – Acquisition, Preservation, and Exchange of Identification Records and Information That category reaches further than traditional police agencies:
- Licensed firearms dealers can verify whether a firearm has been reported stolen.
- Civil and criminal courts can receive NCIC data for use in domestic violence and stalking cases.
- Railroad police and private college police qualify as “other institutions” if they have state-granted arrest powers and devote substantial resources to criminal justice functions.
- Tribal and Bureau of Indian Affairs agencies have explicit authorization for law enforcement purposes.
Beyond NCIC, Congress has created specific screening mandates for workers in sensitive fields. The Affordable Care Act established a National Background Check Program for anyone seeking direct patient access at long-term care facilities, including nursing homes, home health agencies, and hospice providers. That program, administered by CMS in consultation with the FBI, requires fingerprint-based state and federal criminal history checks.5Centers for Medicare & Medicaid Services. CMS National Background Check Program Federal law similarly requires fingerprint-based FBI checks for childcare workers, along with sex offender and child abuse registry checks at both state and national levels.
Private employers, landlords, and volunteer organizations don’t get NCIC access. They use commercial background check databases, and those searches are governed by the Fair Credit Reporting Act. Before running a check, an employer must give you a standalone written disclosure stating that a report will be obtained, and must get your written authorization.6Office of the Law Revision Counsel. 15 USC 1681b – Permissible Purposes of Consumer Reports Burying the disclosure inside a job application or mixing it with other paperwork violates the law.
What Shows Up and for How Long
Not everything in your criminal history can be reported indefinitely by a commercial database. Under 15 U.S.C. § 1681c, a background check company cannot include arrest records more than seven years old. Records of civil suits and civil judgments also fall off after seven years. Criminal convictions, though, have no federal time limit and can be reported forever.7Office of the Law Revision Counsel. 15 USC 1681c – Requirements Relating to Information Contained in Consumer Reports The seven-year arrest limit is a federal floor. Some states impose stricter limits, and a handful ban reporting arrests that didn’t lead to convictions regardless of how recent they are.
There’s one major exception. If the position pays $75,000 or more per year, the seven-year limits on arrests and other adverse items don’t apply, and the background check company can report the full history.7Office of the Law Revision Counsel. 15 USC 1681c – Requirements Relating to Information Contained in Consumer Reports
Expunged and Sealed Records
When a court expunges a criminal record, the FBI deletes it from its Next Generation Identification system entirely. A sealed record works differently: the contributing state tells the FBI which types of inquiries can and cannot access the sealed information, and the FBI restricts dissemination accordingly. The FBI cannot seal or expunge any record on its own. The request has to come from the state identification bureau or the original contributing agency.
The practical problem is that private databases don’t always keep pace with expungements and sealing orders. A commercial aggregator that purchased your court record before the expungement may still have it on file. Under the FCRA, background check companies are required to use reasonable procedures to ensure accuracy, and reporting an expunged record generally violates that standard. But the burden often falls on you to catch the error and file a dispute.
Disputing Errors
If a background check contains inaccurate information, you have the right to dispute it directly with the background check company. The company must then investigate, typically within 30 days, contact the source of the information, and correct or delete anything that can’t be verified. Given that private databases rely on name-matching across thousands of jurisdictions, errors are not rare. Records belonging to someone with a similar name, charges that were dismissed but still show as open, and convictions from states that report inconsistently all turn up regularly.
How to Check Your Own Criminal Record
Anyone can request their own FBI criminal history, called an Identity History Summary, through the FBI’s website. The process requires submitting your fingerprints, either electronically through a Live Scan provider or on a physical fingerprint card, along with an application and processing fee.8FBI. Identity History Summary Checks Because it’s fingerprint-based, it returns any records the FBI has linked to your prints, including arrests, dispositions, and federal records.
An FBI check only covers records that have been submitted to the FBI by state and local agencies. It won’t necessarily include every county-level arrest or court record, particularly from states that submit records voluntarily rather than under the National Crime Prevention and Privacy Compact. As of the most recent data, 37 states have ratified that Compact and are required to share all unsealed criminal history records in response to authorized requests. For a more complete picture, you may need to run a state-level criminal history check in every state where you’ve lived. Most states offer these through their state police or state bureau of investigation for a nominal fee, typically under $25.
Checking your record before a potential employer does gives you a chance to spot errors, confirm that expungements went through, and prepare to explain anything that will show up. For an hour of your time and a small fee, you avoid being blindsided during a hiring process.