On June 27, 2025, leaders from across the country gathered in Chicago for the Machine Gun Conversion Device (MCD) Summit—a full-day event focused on one of the most urgent and complex threats facing public safety today: the illegal modification of firearms into fully automatic weapons. 

Hosted by the Association of Prosecuting Attorneys (APA), and in partnership with the Cook County State’s Attorney’s Office and Chicago Police Department, the summit brought together prosecutors, law enforcement, researchers, and policymakers to share insights, demonstrate emerging threats, and collaborate on solutions. 

A Day of Action and Innovation 

The day began with a live demonstration of machine gun conversion devices, followed by a 3D printing showcase that underscored how easily these devices can be manufactured, distributed, and used. These sessions set the tone for a summit grounded in urgency and realism. 

Throughout the day, attendees engaged in moderated discussions on: 

• Law enforcement and prosecutorial strategies to detect and disrupt MCD use 

• Federal and local perspectives on prosecution and prevention 

• The role of 3D printing and online platforms in the spread of illegal devices 

• Legislative and civil litigation tools to hold bad actors accountable 

Each session emphasized the importance of cross-jurisdictional collaboration and the need for both proactive and reactive strategies. 

Building a Safer Future 

One of the summit’s key takeaways was the power of partnership. Whether through legislative advocacy, community engagement, or interagency coordination, the fight against illegal gun modifications requires a united front. 

The summit also highlighted the importance of innovation—not just in technology, but in how we think about justice, prevention, and accountability. 

What’s Next? 

The conversations started at the MCD Summit won’t end here. APA and its partners are committed to continuing this work through training, policy development, and ongoing collaboration.

Explore the APA’s Gun Violence Resources hub, which includes: 

• “Machine Gun Conversion Devices: Defining the Threat and Taking Action” – A comprehensive guide from APA’s 2024 virtual summit 

• Training materials and model practices for prosecuting MCD-related offenses 

• Legislative and litigation tools to support accountability and prevention 

These resources are designed to extend the impact of the summit and equip stakeholders with the knowledge and tools needed to build safer communities.

📩 Want to learn more or get involved? 

Reach out to Nikki Parisi at Nikki.Parisi@APAInc.org. 

Together, we can build safer communities and stay ahead of emerging threats. 

tags: machine gun conversion devices, gun violence prevention, firearm policy, prosecuting attorneys, public safety, 3D-printed weapons, criminal justice innovation, APA Inc, gun law enforcement, MCD Summit 2025, illegal firearms, cross-jurisdictional collaboration, community safety, firearms litigation, gun violence resources