By Shaina Cole | Contributing Writer, Rocky Mountain Voice
When the Justice Department sued Colorado in May over its large-capacity magazine ban, the state went looking for ammunition of its own. It found it inside DOJ’s filing cabinets.
In its federal court filing on June 30, Colorado submitted a motion to dismiss that leverages two memos from Jeff Sessions, the first attorney general in Trump’s first term. The state utilizes these documents to contend that the DOJ is attempting to assert an authority that its own former leadership said it should not exercise.
The 2017 memo told department heads that “it is not the responsibility of the federal government to manage non-federal law enforcement agencies.” The 2018 memo warned that long-term federal court supervision of state and local governments “can deprive the elected representatives of the people of the affected jurisdiction of control of their government.”
Those memos are now exhibits in a case where the current Trump DOJ is suing Colorado for enforcing its own gun laws.
What DOJ is trying to do
DOJ filed two suits in May. One targets Colorado’s statewide ban on large-capacity magazines in United States v. State of Colorado. The other targets Denver’s assault-weapons ordinance in United States v. City and County of Denver.
The DOJ did not bring either suit as a straightforward Second Amendment case.
Instead it turned to a statute not written with firearms laws in mind. Congress passed 34 U.S.C. § 12601 in 1994 after the Rodney King beating. Its purpose was narrow. It gave the Attorney General a way to sue police departments where officers were using excessive force, running unlawful searches, or engaging in other systemic misconduct.
DOJ’s theory in both Colorado suits is that when state and local officers enforce gun laws that violate the Second Amendment, those officers are engaging in a “pattern or practice” of violating constitutional rights, even if the officers are enforcing a law the state legislature passed.
Colorado’s motion argues that interpretation would give the DOJ a vehicle to challenge “any law enacted by a state’s legislature.”
For more than 30 years, every administration from Clinton through Biden, including the first Trump term, used that statute to go after police departments for excessive force, unlawful stops, discriminatory policing, and similar misconduct by officers.
According to Colorado’s motion and the enforcement history documented in the Civil Rights Division’s own 2017 report, no attorney general ever used it to challenge the validity of a state or local law itself.
The current DOJ’s newly created Second Amendment Section is attempting that for the first time.
Colorado’s motion calls it an “unprecedented” reading of the statute, and the 30-page filing, by Deputy Solicitor General David Moskowitz and a team from AG Phil Weiser’s office, asks the court to throw the case out before the Second Amendment question is ever reached.
Why Colorado says the statute doesn’t fit
The motion’s argument starts with the statute’s own language. The law targets “a pattern or practice of conduct by law enforcement officers.”
Colorado contends that phrase was written to cover how officers behave on the job, not what a state legislature enacted.
The General Assembly passed the magazine ban in 2013. Law enforcement officers enforce it because they are required to enforce state criminal law. That enforcement is not “conduct by law enforcement officers” in the sense Congress meant, the state argues. It is a legislative act by a different branch of government.
A January 2017 Civil Rights Division report, also attached as an exhibit, documents the statute’s entire enforcement history. Every prior case targeted officer conduct such as unlawful force, discriminatory stops and officer theft. None challenged a law passed by a legislature.
The fourth exhibit is the letter that started this fight.
On April 28, 2026, Harmeet Dhillon, the assistant attorney general who leads the DOJ’s Civil Rights Division, wrote to Governor Jared Polis and AG Phil Weiser.
According to Colorado’s motion, the letter said the DOJ intended to sue unless Colorado agreed to negotiate terms that would require the state to stop enforcing the magazine ban, declare it unconstitutional, and accept a permanent injunction.
Colorado did not agree. The DOJ filed the Colorado suit eight days later, on May 6.
Even if DOJ wins, Colorado says nothing changes
The DOJ sued the State of Colorado and the Colorado Department of Public Safety, the agency that houses the State Patrol and the Colorado Bureau of Investigation.
Even a complete DOJ victory, the state argues, would bind only those defendants. It would not bind Colorado’s elected district attorneys, who hold independent prosecutorial authority under the state constitution. It would not bind the roughly 240 local law enforcement agencies across the state, nor the sheriffs in all 64 counties.
Violations of the magazine ban could still be investigated, charged and prosecuted the day after the DOJ obtained a judgment, the motion argues. It cites a 2023 Supreme Court case, Haaland v. Brackeen, for the principle that a court cannot remedy an injury when the officials who would keep causing it are not parties to the lawsuit.
The DOJ also departed from the standard pattern-or-practice process, Colorado notes.
There was no public investigation, no ride-alongs, no community town halls, no findings letter and no negotiated reform agreement. Those are the steps the Civil Rights Division’s own 2017 report describes as standard.
Apart from the Dhillon demand letter, the department went straight to a complaint.
Both cases now sit before one judge
Federal court records show that the DOJ’s two Colorado gun-law suits are now proceeding before the same federal judge.
On June 26, with Chief Judge Daniel D. Domenico’s approval, the Colorado case was transferred to District Judge S. Kato Crews. Three days later, Magistrate Judge Kathryn A. Starnella issued a minute order finding the Colorado case “is related to an earlier filed case, United States v. City and County of Denver.”
That companion case was already before Judge Crews, who had been issuing orders in it since June 4.
Both sides have asked for extra pages to make their arguments. Colorado’s request was granted June 24 by District Judge Gordon P. Gallagher, two days before the case was transferred to Judge Crews.
On July 10, the DOJ filed an unopposed motion for leave to file a 30-page response, signed under the authority of Dhillon and listing Barry K. Arrington as Acting Chief of the Second Amendment Section. Judge Crews granted it the same day. As of July 21, the DOJ had not yet filed its response.
Denver is next
In the companion case, Denver has until July 23 to respond to the complaint.
The city’s legal team includes the Denver City Attorney’s office and Everytown Law, the litigation arm of Everytown for Gun Safety. Denver has signaled it plans to file a motion to dismiss.
The joint status report filed June 30 stated Denver “plan[s] to file a motion to dismiss and believe[s] that any scheduling conference should be held until after the Court resolves that motion.”
On July 17, Denver filed an unopposed motion for extra pages ahead of its July 23 deadline.
Denver’s motion has not been filed yet, so whether its arguments track Colorado’s or take a different approach is not yet known. What is known is that Judge Crews will decide the threshold legal question in both cases.
Can the pattern-or-practice statute Congress wrote to address police brutality be used to challenge the validity of state and local firearms laws themselves?
If the answer is no, the DOJ loses its vehicle for both suits.