Case Explained: Vital City | How Criminals Get Their Guns – Legal Perspective

Gangs, drug-selling crews and other criminal organizations generate a disproportionate amount of gun violence in U.S. cities. While these groups drive much of the shooting and homicide plaguing urban neighborhoods, most people (including many policymakers) don’t understand how these dangerous actors actually acquire their weapons.

City-level studies reveal the stark concentration of gun violence among criminal networks. Gang- and group-involved conflicts drive more than one-third of homicides in Chicago, half in Los Angeles’ Boyle Heights area and nearly two-thirds in Oakland. A study of more than 20 cities found that less than 1% of a city’s population was involved in gangs, drug crews and other criminally active groups, but they were connected to over 50% of shootings and homicides.

This concentration creates both a challenge and an opportunity. While a small number of high-risk individuals drive most gun violence, it also means that disrupting their access to firearms could have outsized effects on urban safety.

Contrary to popular belief, gang members, drug dealers and other serious criminals generally do not obtain their guns by purchasing them from licensed dealers. Instead, they acquire weapons through informal transactions in underground markets supplied by guns diverted from legal commerce.

A 2016 federal survey of state prison inmates found that fewer than 10% purchased their last firearm at a gun store or pawnshop. Instead, gun criminals tend to acquire their firearms from family members, friends, acquaintances and connections to the underground economy such as fences, drug dealers and other “street” sources.

This reality points to a crucial fact: The primary challenge isn’t stopping criminals from buying guns legally — federal law already prohibits most of them from doing so. The real challenge is stopping the flow of weapons from legal markets into illegal ones.

Inside the underground gun market

Data from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) provides a window into these underground markets. Between 2017 and 2021, ATF traced nearly 2 million crime guns recovered by law enforcement agencies. The patterns revealed tell a compelling story about how illegal gun markets operate.

Most traced crime guns were semiautomatic pistols with medium and large calibers — the weapons of choice for urban violence. Pistols accounted for 68% of recovered crime guns, with their share increasing to 75% by 2021. Almost half were 9mm firearms, primarily from quality manufacturers like Taurus and Glock, Smith & Wesson.

Perhaps most revealing is what ATF investigators and researchers call “time-to-crime” — the period between a gun’s last legal purchase and its recovery in a crime. Short time-to-crime periods indicate trafficking, as legitimate gun owners rarely have their recently purchased weapons show up at crime scenes. Between 2017 and 2021, 25% of traced crime guns were recovered within one year of purchase and 46% of traced crime guns were recovered within three years of purchase, and these percentages increased dramatically during the study period.

Even more telling: Only 12% of traced crime guns were recovered from their original purchaser. Most had changed hands multiple times through underground networks, often very quickly after their initial legal sale.

Crime gun traces also reveal the geographic patterns of illegal gun flows. Location data show that firearms migrate from states with less restrictive gun controls to states with more restrictive laws. States with strong gun controls like New Jersey (82%), New York (80%) and Massachusetts (67%) have high percentages of traced crime guns originally purchased in other states. Meanwhile, states with weaker controls like Texas (86%), Wisconsin (84%) and Ohio, Virginia and Indiana (all 83%) see most of their crime guns purchased locally.

This interstate flow creates what law enforcement officials and researchers call “iron pipelines” — well-established trafficking routes that move weapons from states with lax gun laws to cities with stronger controls but higher demand from criminal networks.

The pathways of illegal diversion

ATF investigation data reveals the specific channels through which guns move from legal to illegal markets. Unlicensed dealing by private persons (40.7% of cases) and straw purchasing from licensed dealers (39.5%) are the most frequent trafficking methods.

Straw purchasing — where someone legally eligible to buy guns purchases them for prohibited persons — represents a particularly important pipeline. These buyers can receive significant markups for their services. Research in Boston found that gang members and drug dealers paid nearly 200% markup over fair market value for handguns acquired through trafficking networks.

Other significant sources include theft from licensed dealers (17.3%), theft from private persons (7.9%) and increasingly, privately made firearms or “ghost guns.” The number of these unserialized, homemade weapons recovered in crimes increased by nearly 1,100% between 2017 and 2021.

Research in cities like Boston, Chicago and New York City reveals how criminal networks facilitate gun access among their members. Gang membership significantly eases access to firearms through established supply lines and shared connections. As one gang member explained to researchers: “Basically, people in gangs … they got guns ready … They know more people … got more connects.”

These networks don’t just share weapons — they share suppliers. Gang members pool their connections, meaning that disrupting access for one member can affect the entire network’s supply chain.

Studies also show that gang members tend to acquire older firearms that have changed hands multiple times, suggesting they’re purchasing from established trafficking networks rather than directly from recent legal sales. In Boston, traced guns recovered from gang members had a median age of 14 years, compared to 10 years for guns recovered from non-gang members.

Underground gun markets operate differently from legal markets due to their illegal nature. Research in Chicago found these markets are “thin” — meaning few buyers, sellers and total transactions — with considerable friction that makes guns harder to obtain for some participants.

This friction creates opportunities for law enforcement. The underground gun market doesn’t operate under the law of one price. Instead, access and cost depend heavily on “who you know.” Even within criminal networks, many actors cannot successfully purchase guns, while others — particularly gang members — have easier access through established connections.

Privately-made firearms represent an emerging and concerning trend. These weapons, assembled from kits or parts, bear no serial numbers and are untraceable. While they required some technical skill in the past, today’s kits can be assembled with basic tools and online instructions.

In Oakland, the percentage of ghost guns among all recovered crime guns increased from 1% in 2017 to almost 25% in 2021. Research suggests criminals prefer these untraceable weapons for violent crimes, as they cannot be connected back to specific purchasers through ATF tracing systems.

In 2022, the Biden administration enacted Final Rule 2021R-05F, which included several important reforms such as a requirement for licensed dealers to identify privately made firearms with serial numbers before entering regulated commerce. Multiple states have also passed legislation regulating privately-made firearm commerce and possession. It remains unclear whether these reforms have produced the desired impacts.

What works: disrupting underground markets

Despite the challenges, research shows that law enforcement can effectively disrupt underground gun markets through strategic, problem-oriented approaches. The key is understanding local market dynamics and targeting specific trafficking channels rather than just focusing on possession.

The gun market disruption strategy implemented as part of Boston’s Operation Ceasefire suggests a successful model. Based on analysis of local gun trafficking patterns, the intervention focused enforcement on new handgun diversions from retail outlets. The strategy included expanded focus on both interstate and intrastate trafficking, attention to guns with short time-to-crime intervals, and systematic tracing and investigation of firearms used by violent gangs.

The results were significant: The percentage of new handguns recovered by Boston police decreased substantially, suggesting the strategy increased the “effective price” of acquiring new firearms for criminal use.

Similar approaches in Detroit, Chicago and Milwaukee have shown notable changes to local gun market dynamics. In Los Angeles, a simple intervention sending letters to new gun buyers about their legal responsibilities resulted in higher rates of theft reports — suggesting some buyers were using theft reports to distance themselves from future misuse.

The path forward

The evidence suggests several promising directions for reducing criminal access to firearms:

Focus on secondary markets. Since criminals rarely purchase guns directly from dealers, closing loopholes in private sales and better regulating secondary markets could significantly impact criminal access.

Target trafficking networks. Law enforcement should focus on the intermediaries — straw purchasers, brokers and traffickers — rather than just end users.

Comprehensive tracing. All recovered crime guns should be traced and analyzed to identify trafficking patterns and suspicious purchase activities.

Problem-oriented approaches. Successful interventions require understanding local market dynamics and tailoring enforcement strategies accordingly. This approach could be particularly effective in addressing local gun theft problems.

Interstate coordination. The geographic patterns of gun trafficking require coordinated responses across state lines, particularly between source and destination jurisdictions.

Stemming the flow of illegal guns to gangs and violent groups requires adequate resources and sustained commitment. Success against underground gun markets demands separating firearms trafficking strategy from broader gun politics and focusing on evidence-based approaches.

Local police departments should take problem-oriented approaches to understand how criminals access guns in their specific jurisdictions and collaborate with federal and state partners to implement targeted interventions. The concentration of gun violence among small numbers of criminal actors creates an opportunity: disrupting their access to firearms could yield significant reductions in urban gun violence.

The underground gun market isn’t unstoppable. It operates with friction, inefficiencies and vulnerabilities that smart policing can exploit. But success requires understanding how these markets actually work — not how we assume they work — and designing interventions based on evidence rather than assumptions.

As cities continue to grapple with gun violence, focusing on the supply chains that arm the most dangerous actors represents one promising path toward safer communities.