Reviewed and updated October 9, 2026 by the SearchSystems.net editorial team. The arrest and crime counts are the ones each agency reported to the FBI, as the FBI held them on October 8, 2026. Every office link was opened and checked against the office's own site between September 23, 2026 and September 25, 2026.
Thornton, Colorado, in Adams County, has about 147,000 residents (2024 Census Bureau estimate). In Colorado the public criminal record is the court file, kept by the clerk of the combined court; the statewide criminal history kept by the Colorado Bureau of Investigation is open to anyone who asks. This guide says where each record of a criminal case from Thornton is kept and how it is seen.
This guide covers the court file, the statewide record, local arrest records, the crimes behind the records, sex offender registry, records requests and common questions.
Related guides: Thornton public records, Adams County criminal records, Thornton arrest records, Thornton warrants, Thornton inmate search, Thornton court records, Colorado arrest records and Colorado inmate search.
Criminal Cases in the Adams County District Court
In Colorado the public criminal record is the court file. Criminal cases from Thornton are heard by the Adams County District Court, which hears felonies, civil cases over $25,000, divorces, probate and juvenile matters; the County Court takes misdemeanors, traffic cases and civil cases up to $25,000, and the file of each case is kept by the clerk of the combined court.
The court records page SearchSystems verified for the county is at coloradojudicial.gov/courts/trial-courts/adams-county (page title: Adams County | Colorado Judicial Branch), phone 303-659-1161, 1100 Judicial Center Dr. Brighton, CO 80601, Monday-Friday: 7:30 a.m. - 5:00 p.m., which answered when SearchSystems opened it on September 23, 2026.
Colorado has no single public index of every trial court case; each court's records are looked up through that court.
The Colorado Criminal History and Your Own Copy
Colorado is one of the states that lets anyone look up another person's statewide criminal history: the state runs an online name-based criminal history check open to the public, through the Colorado Bureau of Investigation. The result is the repository record, what agencies reported to the state, which is wider than one county's court index but can lag it.
To see your own record, the route is a name-based or fingerprint-based request to the Colorado Bureau of Investigation. The state page SearchSystems verified for it is at cbi.colorado.gov/records-background-checks/internet-criminal-histor....
Arrest Records Kept Locally in Thornton
The Adams County Sheriff's Office and the agency that reports for Thornton (filed by the FBI as Thornton Police Department) keep the arrest records in and around Thornton: the report and the booking record of each arrest stay with the agency that made it, separate from the court file and from the state repository.
The FBI's agency list also places one more agency in Adams County: the University of Colorado at Denver (campus police); it keeps the records of its own arrests.
The Arvada Police Department and the Aurora Police Department are each listed by the FBI across several counties including Adams County, so their arrests are not broken out for Adams County here.
Together, the seven agencies in Adams County with all twelve months of 2025 on file reported 21,118 arrests to the FBI that year; how each case ended is in the court file, not in the arresting agency's.
The agencies and their counts, year by year, are in Thornton arrest records.
The Crimes Behind the Records: Thornton in 2025
The agency that reports for Thornton had 371 violent and 3,378 property crimes reported for 2025; each one is a report on file with it, and each arrest that follows is the start of a criminal record.
The Sex Offender Registry for Thornton
Registered sex offenders living in Thornton are listed on the Colorado Sex Offender Registry, run by the Colorado Bureau of Investigation at apps.colorado.gov/apps/dps/sor. Only sexually violent predators, multiple offenders and adults convicted of felony sex offenses appear on the statewide site; local police and sheriffs hold the full list.
Registration itself is done in person with the local agency where the registrant lives: the sheriff's office, or the city police in a city with its own department.
Asking an Agency in Adams County for a Record
An arrest report, a booking record or a local criminal history letter comes from the agency that holds it, not from the court.
Under the Colorado Open Records Act a county office must answer a request within 3 working days, extendable to 7 when there are extenuating circumstances, and it may charge research and retrieval time after the first hour, plus copying.
Frequently Asked Questions
Are criminal records public in Thornton?
The court files of criminal cases are public, and so is the statewide criminal history kept by the Colorado Bureau of Investigation: the state runs an online name-based criminal history check open to the public. The arrest report itself is released by the agency that made the arrest, under the Colorado Open Records Act.
Can I search Thornton criminal cases online?
The court records page SearchSystems verified for the county is at coloradojudicial.gov (page title: Adams County | Colorado Judicial Branch).
How do I get my own Colorado criminal history?
Through a name-based or fingerprint-based request to the Colorado Bureau of Investigation.
Is this the official Thornton website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official city, county, court and state offices described above and does not hold records, charge for them or take requests.