A federal firearm case in Denver, CO rarely stays confined to the gun itself. One allegation can trigger mandatory prison terms, add time to another sentence, put your firearms at risk of forfeiture, and affect your rights long after the case ends. ATF agents and the U.S. Attorney’s Office frequently pursue these charges as part of broader investigations involving drug trafficking, federal conspiracy, robbery, or violent crimes.
The gun does not have to be used in the way most people imagine. Federal charges may grow out of constructive possession, a straw purchase, false statements to a dealer, access to an unregistered weapon, or a firearm found near alleged criminal activity. In some cases, the firearm allegation is what turns a difficult prosecution into one carrying years of additional prison exposure.
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Combs Waterkotte represents clients in Denver, CO when a federal firearm investigation puts their freedom and future on the line. Our federal criminal defense attorneys serving Denver, CO dig into the government’s theory from every angle, including where the gun was found, who allegedly controlled it, how officers obtained the evidence, and whether the weapon had any real connection to another offense.
If you have been arrested, received a target letter, learned that ATF agents are investigating you, or believe federal charges may be coming, contact us online or call (314) 900-HELP immediately. What happens before an indictment can shape the entire case.
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Below, we explain:
- What gives the federal government authority over a firearm case
- What not to do when you learn you are under investigation
- Which federal gun charges prosecutors commonly file
- How consecutive sentences and enhancements can increase prison exposure
- Why the Armed Career Criminal Act can change the entire case
- How a federal gun charges lawyer can intervene
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How Federal Jurisdiction Applies to Gun Cases
The line between a state gun case and a federal prosecution is not always obvious. A case may cross that line because of the weapon involved, the accused person’s legal status, the location of the alleged conduct, or a claimed connection to interstate commerce. Violations of the Gun Control Act, the National Firearms Act, or another federal statute may give the U.S. government authority to prosecute. Local agencies can also refer cases upward when they want federal prosecutors to pursue harsher consequences.
Federal prosecutors may become involved if:
- A prohibited person allegedly possessed a gun or ammunition
- The weapon allegedly traveled in or affected interstate or foreign commerce
- The firearm was supposedly used, carried, or kept in connection with another federal crime
- The investigation concerns illegal sales, straw buyers, trafficking networks, or cross-border smuggling
- The gun falls into a specially regulated category under federal law
- Authorities discover a defaced or missing serial number
- The incident happened on federal property or during another federal investigation
- The government believes the weapon played a role in organized criminal activity
By the time a person learns about the investigation, agents may already have collected surveillance footage, phone records, social media posts, witness statements, firearm traces, and forensic evidence.
How to Protect Yourself During an ATF Investigation in Denver, CO
Federal investigations usually develop quietly. If agents have reached out, searched your property, questioned someone close to you, or asked you to “clear a few things up,” assume the case is already moving. You should treat every conversation and decision as part of the defense.
If you believe you are under investigation for a federal firearm offense:
- Exercise your right to remain silent. You do not need to answer questions from ATF agents, task force officers, or federal prosecutors without a federal firearms attorney in Denver, CO present. What feels like harmless background information can become evidence.
- Do not give blanket consent. If law enforcement has a valid warrant, let your lawyer challenge it later. Do not voluntarily open additional devices, accounts, rooms, safes, or vehicles unless counsel advises you to do so.
- Do not erase the paper trail. Keep purchase forms, receipts, emails, photographs, texts, and other records intact. Destroying or altering evidence can make the situation far worse.
- Say less to everyone else, too. Friends, relatives, coworkers, and alleged associates can be interviewed or subpoenaed. Social media posts and private messages are not safe places to explain the case.
- Contact a federal criminal defense lawyer in Denver, CO immediately. The earlier your attorney enters the case, the sooner they can protect your rights, identify weak points in the investigation, and keep you from stepping into traps the government has already set.
Federal Firearm Offenses Charged in Denver, CO
Unlawful Firearm Possession Under 18 U.S.C. § 922(g)
The phrase “felon in possession” covers only part of 18 U.S.C. § 922(g). The statute reaches multiple classes of people barred from possessing guns or ammunition, even when the firearm was never fired or displayed.
Prohibited persons may include:
- People convicted of crimes punishable by more than one year in prison
- Fugitives from justice
- Unlawful users of controlled substances
- Certain people subject to domestic violence restraining orders
- People convicted of qualifying domestic violence offenses
- Certain noncitizens and people dishonorably discharged from the military
A conviction ordinarily requires more than showing that a gun was nearby. The government generally must prove knowing possession and that the accused knew they belonged to the category that prohibited possession.
A gun does not necessarily have to be found in someone’s hand or clothing. Prosecutors may allege:
- Physical possession: The firearm was allegedly recovered directly from the accused.
- Constructive possession: The government argues that the accused exercised dominion or control over the firearm even though someone else may have been closer to it.
Shared spaces create room for reasonable doubt. If the firearm was found in a jointly occupied apartment, another person’s car, a motel room, or an area open to multiple people, prosecutors still must tie the accused personally to the weapon.
Federal Gun Enhancements for Drug and Violent Offenses
A firearm allegation can become its own criminal count when it is tied to certain drug or violent offenses. Under 18 U.S.C. § 924(c), prosecutors may charge a person with using or carrying a gun during a qualifying offense or possessing one to advance that offense.
The statute carries mandatory minimum prison terms that generally run back-to-back with the sentence imposed for the related offense:
- A five-year minimum for qualifying possession, use, or carrying
- A seven-year minimum when prosecutors prove brandishing
- A 10-year minimum when the firearm was discharged
- Longer mandatory terms for certain machine guns, suppressors, and destructive devices
No shot needs to be fired for prosecutors to bring this charge. They may claim the firearm helped secure, protect, or advance the alleged operation because it was located close to:
- Illegal drugs
- Cash
- Packaging materials
- Distribution records
- Other alleged evidence of trafficking
Proximity alone may not tell the whole story. The defense may argue that the firearm belonged to someone else, was inaccessible, was present for an unrelated lawful reason, or did nothing to promote the alleged offense.
Straw Purchasing a Firearm
The government may call a transaction a straw purchase when it believes the person at the counter was not the firearm’s true purchaser. What looked like a simple favor, gift, or shared shopping trip may be scrutinized through purchase records, ATF Form 4473, and the federal straw purchasing statute.
These cases may depend on:
- Payment apps, cash withdrawals, or reimbursements
- Who researched, requested, or picked out the firearm
- The buyer’s plan before entering the store
- Whether the gun was genuinely purchased as a gift
- Whether the eventual recipient was prohibited or intended to use the firearm unlawfully
Agents may build the case from messages, bank or payment-app records, dealer paperwork, surveillance video, and whatever the purchaser or recipient said during interviews.
Federal Firearms Trafficking Charges
18 U.S.C. § 933 prohibits certain transfers, transportation, or receipt of firearms when the accused knows or has reasonable cause to believe the firearm will be used, possessed, or transferred unlawfully.
Conduct that may lead to a federal trafficking charge includes firearms being:
- Bought for someone legally barred from possessing them
- Transported through multiple states or across an international border
- Transferred to people suspected of drug or violent offenses
- Obtained through a chain of straw buyers
- Repeatedly resold outside the federal licensing system
- Exported or smuggled to another country
Selling Guns Without a Federal Firearms License
Federal law generally requires a person who is engaged in the business of dealing firearms to obtain a federal firearms license. An occasional private sale does not automatically make someone a firearms dealer.
The case may turn on the overall pattern of activity, including:
- The number and frequency of sales
- How quickly firearms were resold after purchase
- Whether the accused advertised firearms for sale
- Customer communications and payment records
- Whether transactions were intended to produce a profit
- Whether the accused maintained firearm inventory
Federal Charges for False Firearm Purchase Statements
A mistake on firearm paperwork is not necessarily a federal crime. Under 18 U.S.C. § 922(a)(6), the government must generally show that the accused knowingly provided false information about something that mattered to the dealer’s decision.
Examples of information prosecutors may claim was falsified include:
- The actual transferee or intended recipient
- Felony or other prohibiting convictions
- Unlawful drug use
- Domestic violence history or court orders
- Nationality and immigration status
- Personal identification and residence information
A discrepancy is not the end of the story. Defense counsel may argue that the accused misunderstood the question, relied on incorrect information, did not knowingly lie, or gave an answer that did not affect whether the firearm could be sold.
Federal Charges Involving an Altered Firearm Serial Number
A damaged or missing serial number can create separate federal exposure. Under 27 CFR § 478.34, the government may prosecute certain knowing possession, transportation, or receipt of a firearm with altered identifying marks.
The serial number itself is only part of the case. Other issues include:
- Whether the alteration was visible or known to the accused
- Whether the serial number was legally “removed, obliterated, or altered”
- What laboratory testing reveals about the original markings
- Whether prosecutors can prove knowing possession of that specific gun
The alleged alteration can affect more than guilt or innocence. It may also support an enhancement when the sentencing guidelines are calculated.
Privately Made Firearms and “Ghost Guns”
The label “ghost gun” can make a case sound simpler than it is. A privately assembled firearm may be lawful in some circumstances, while its possession, manufacture, sale, or markings may create federal exposure in others.
The government may try to build its case around:
- Possession by a prohibited person
- The number and type of firearms produced
- Messages or payments showing planned sales
- Whether the accused acted as an unlicensed manufacturer or dealer
- The absence of markings required under federal law
- The use or presence of the firearm during another alleged offense
Sentencing enhancements may also apply in some cases involving firearms without required serial numbers.
Federal National Firearms Act Charges
Certain firearms and devices are subject to stricter federal controls under the National Firearms Act. The law regulates their registration, manufacture, taxation, possession, and transfer.
NFA-regulated firearms include:
- Machine guns
- Short-barreled rifles
- Short-barreled shotguns
- Silencers and suppressors
- Destructive devices
- Certain weapons classified as “any other weapon”
Charges may involve possessing an unregistered weapon, illegally manufacturing or transferring one, or possessing a firearm with required identifying information removed. A conviction can carry up to 10 years in federal prison, fines, and forfeiture.
Penalties for Federal Gun Charges in Denver, CO
Two people charged with firearm offenses may face very different outcomes. Federal sentencing depends on what prosecutors can prove, which statute applies, whether the law requires consecutive time, the accused’s criminal history, and how the court calculates the advisory guideline range.
| Federal Firearm Charge | Possible Federal Sentence |
|---|---|
| Felon in possession or another prohibited-person offense | Ordinarily punishable by as much as 15 years; the Armed Career Criminal Act may require at least 15 years for qualifying defendants |
| Possessing, carrying, or using a firearm during a drug trafficking crime or crime of violence under § 924(c) | Five years or more added to the underlying sentence, with seven years for brandishing and 10 years for firing the weapon |
| Federal straw purchase allegations | As much as 15 years, with enhanced exposure of up to 25 years in qualifying aggravated cases |
| Unlawful transportation or transfer of firearms | A possible sentence of as much as 15 years |
| Engaging in the business of firearm sales without federal licensing | Typically punishable by up to five years |
| Knowingly providing material false information to a licensed firearm dealer | As much as a decade in federal custody |
| Knowing possession of a gun with a removed or changed serial number | Typically punishable by as much as five years, and the serial-number issue may also raise the guideline range |
| National Firearms Act violations | Potentially a decade in federal custody, plus monetary penalties and seizure of the firearm |
| Possessing or transferring a prohibited automatic weapon | Often up to 10 years, with substantially greater exposure when connected to a drug trafficking crime or crime of violence |
These are general statutory penalties. The actual sentencing range may depend on the specific charge, the type and number of firearms involved, the defendant’s criminal history, applicable mandatory minimums, and the United States Sentencing Guidelines.
Federal sentences may also include:
- Fines and court-ordered financial obligations
- Post-release supervision with strict federal conditions
- Forfeiture of the firearm and other property allegedly connected to the offense
- The loss of federal firearm rights
- Difficulty finding employment, securing housing, or keeping a professional license
- Serious immigration consequences, including possible deportation exposure
A federal sentence is not typically cut short through parole. Although some prisoners can earn good-conduct credit, federal incarceration generally means serving the great majority of the term imposed.
How the Armed Career Criminal Act Can Increase a Gun Sentence
A standard felon-in-possession prosecution can take a drastic turn when prosecutors invoke the Armed Career Criminal Act. If the enhancement applies, the sentencing floor becomes 15 years in federal prison.
The government generally must identify at least three qualifying prior convictions for violent felonies or serious drug offenses. It must also show that those offenses were committed on occasions separate from one another.
ACCA litigation can become highly technical. The court may compare the wording of the prior state statute to the federal definition, review charging papers or plea records, and determine which version of the law controls. A state-law label is not necessarily the final word.
Potential ACCA challenges include:
- Whether the statute of conviction is broader than ACCA’s federal definition
- Whether the government can prove the specific subsection or elements involved
- The timing, location, and relationship between the alleged prior offenses
- Vacatur, expungement, pardon, or other relief affecting a conviction
- Any restoration of civil and firearm rights
When three qualifying convictions are required, knocking out one may knock out the entire 15-year mandatory minimum. That can completely reshape the sentencing landscape.
Federal Guideline Enhancements for Gun Charges
Avoiding a mandatory minimum does not necessarily mean avoiding a lengthy sentence. Federal judges begin by calculating the advisory guideline range, and enhancements can dramatically increase that recommendation.
The advisory guideline range may increase if the government proves factors such as:
- Possessing numerous firearms
- Guns reported stolen
- Removed, altered, or unreadable serial numbers
- Supplying firearms to prohibited individuals or trafficking activity
- Machine guns, suppressors, destructive devices, or other NFA-regulated weapons
- Using or possessing a firearm during another felony offense
- Dangerous conduct while attempting to flee law enforcement
- Directing or organizing other participants
- Acts prosecutors characterize as obstruction
The advisory guideline range is only one part of the sentencing decision, but it carries significant weight. Defense counsel may dispute factual allegations, challenge the legal basis for enhancements, present mitigating information, and advocate for a sentence below the recommended range.
Do You Need a Federal Gun Charges Lawyer?
Federal investigations often begin long before anyone is arrested. Speaking with a federal defense lawyer as soon as you suspect you are involved may help protect your rights from the very beginning.
Common signs that federal authorities may be building a case include:
- ATF, FBI, DEA, or task force agents attempt to question you
- Agents execute a search warrant at your home or business
- Someone close to you receives a subpoena
- Law enforcement seizes firearms, phones, computers, or records
- You receive a federal target letter
- A codefendant or alleged associate is arrested
- A state firearm case is dismissed or delayed without explanation
- You learn that federal prosecutors are reviewing your case
Getting a lawyer involved early may allow your attorney to deal directly with investigators, advise you before questioning occurs, preserve favorable evidence, evaluate search issues, assess your potential exposure, and advocate with prosecutors before formal charges are filed.
Speak With a Federal Gun Charges Lawyer in Denver, CO
Combs Waterkotte represents Denver, CO clients in complex federal criminal cases across the United States. Our attorneys include former prosecutors who understand how federal cases are investigated, charged, and tried.
We approach every case with a trial-ready mindset, thoroughly examining the government’s evidence, challenging unlawful searches and seizures, scrutinizing witness credibility, and fighting unsupported sentencing enhancements.
If a negotiated resolution serves your interests, we pursue it with leverage built through preparation. If the government will not offer a fair outcome, we are ready to litigate the case in court.
From investigating the government’s theory to preparing for appeal, our team is equipped for the full life of a federal firearm case. Clients benefit from decades of combined experience, dedicated investigative support, and a record of defending people facing life-changing criminal accusations.
A federal gun investigation can gain momentum long before an indictment is returned. Reach out to our firm online or call (314) 900-HELP today to discuss your options with a Denver, CO federal firearm defense lawyer.

