Uncovering Ghost Guns: Minors are Most Engaged Demographic on Social Sites

People discussing Ghost Guns on Reddit are most likely to be under 21

This is the third in a series of blog posts describing how ghost guns—privately manufactured firearms (PMFs)—are being discussed on social media and the associated impacts to gun violence in the US. As described in our first blog, ghost guns have become increasingly prevalent in gun-related crimes across the US, likely because they cannot be traced (meaning, there is no record of ownership transactions, which often assist police in identifying suspects or crime gun sources), and they can be accessed by people who are legally prohibited from firearm possession.

By comparison, traditional federally licensed firearm dealers (FFLs) are required to follow local state law and must have potential purchasers fill out a Form 4473, which is then submitted to the National Instant Criminal Background Check System to confirm that the potential purchaser does not have a background that makes them prohibited (such as a felony conviction or a domestic abuse conviction). Before the Form 4473 even enters the picture, however, federal and state laws also prohibit people below certain age limits from purchasing firearms. This blog discusses what is known about underage purchasers of ghost guns generally and what can be learned from Reddit specifically—those engaging in conversation are most likely to be under 21.

Federal law requires that individuals seeking to purchase from FFLs be at least 18 years of age to purchase a long gun (including assault weapons) and 21 years of age to purchase a handgun—ghost guns can be either. For unlicensed firearm dealers, federal law places no limits on long gun purchasers and requires handgun purchasers to be 18. About half of states have more restrictive laws than federal statute, often requiring purchasers to be 21 years of age regardless of the seller. However, in many states minors could skirt these laws by purchasing ghost gun build kits, which have disassembled gun parts. These kits are currently legal and do not meet the definition of a firearm. However, once assembled, the weapon will meet the definition of a firearm and is subject to state and federal laws regarding possession by a minor.

What do we know so far about underage interactions with ghost guns?

Very little is known about how frequently underage individuals access ghost guns, but there is anecdotal evidence that they have become increasingly common in school shootings and unintentional shootings involving minors. Everytown for Gun Safety maintains a log of examples of ghost gun shootings and recoveries from across the US. 

One of the challenges to collecting data on ghost guns is that law enforcement data systems have not yet separately classified these new events. For example, the National Incident Based Reporting System (NIBRS), which will soon be the nationwide system for detailed crime information, does not currently have a gun type category for recording ghost guns. Even the ATF, which has perhaps the most reliable data on this topic, is struggling to categorize and disseminate information to law enforcement about how and when to report “untraceable” weapons to the National Tracing Center. These data, however, only capture ghost gun usage in crimes and do not convey demographic information about the perpetrator.

Why turn to Reddit for ghost guns research?

The lack of reliable data on who is most interested in possessing ghost guns led our team to nontraditional data sources, such as Reddit, to describe the ghost gun market among young people. For example, young people may turn to Reddit to learn more about whether they can legally purchase a ghost gun and what the consequences may be, given the complex legal landscape. Or, as discussed in our second blog, they may be interested in how to buy ghost gun components and how to build a ghost gun. 

RTI developed an age prediction algorithm designed to categorize Reddit users into two age groups: 13-20 and 21-54. This model, which was originally used for studying online discussions around vaping and e-cigarettes, was applied to a dataset of Reddit users who either posted about ghost guns (e.g., using terms like "ghostgun," "3dprintedgun," or "poly80") or posted on a ghost gun subreddit (e.g. r/FOSSCAD, r/Polymer80, r/DIYGuns).  Between January 2020 and August 2024, we predicted age groups for 82,961 users and estimated proportions and confidence intervals of users per age group using 1000 bootstrap samples.

What did we find about minors and ghost guns Reddit discussions?

The majority of participants were predicted to be under 21 years of age and contributed 89.6% of total posts and comments. The remaining 16.3% of authors, aged between 21 and 54, were responsible for 10.4% of the content. Both groups contributed to the ghost gun topic equally—around 24 posts per author—demonstrating a high level of engagement from both groups. This was much higher than our team initially hypothesized but it is consistent with the conventional wisdom that ghost guns are likely more appealing to people who are either unable to obtain firearms for legal reasons or unwilling to obtain them through the traditional market because they are intended for illicit purposes. This finding is consistent with several decades of research on the age-crime curve for violence indicating that population rates of violence increase throughout early adolescence, peak in the late teenage years, and taper throughout the 20’s.      

To strictly interpret these estimates, several assumptions about the use of the age algorithm and Reddit data are required, including:

1. People who self-report age on Reddit (training set) are exchangeable for those who do not self-report.
2. No data drift has occurred since the model was trained, meaning that we assume that the accounts we’re predicting have the same age and covariate distribution as the training data, and that the functional relationship between the covariates and age hasn’t changed since the algorithm was developed.

If these assumptions are not met, it is possible that the algorithm inflates the number of conversations happening among people under age 21. However, these findings do provide evidence that the majority of these conversations are likely taking place among individuals whose youth places them at the highest relative risk for violent crime compared to other age groups.

Understanding the Rise of Ghost Gun Purchases Among Young People

This exploratory analysis draws attention to the urgency of better understanding who is purchasing ghost guns, and why. Our results suggest that most people discussing ghost guns on Reddit are under age 21. This finding may reflect that people who are underage or otherwise prohibited from firearm possession and may have previously stolen guns out of cars or homes, could now be turning to ghost guns. 

Compared to theft, accessing ghost guns online is safe and easy, particularly with sources such as Reddit providing up-to-date building guidance and a community that normalizes ghost gun possession. These considerations greatly reduce criminal justice and knowledge barriers that previously discouraged prohibited people from accessing guns. To better understand these trends, our final blog post makes suggestions for further research.