As the lead law enforcement officer for Queens County, I have seen a new, and dangerous, trend emerge — the building of personally manufactured firearms or “ghost guns” in residents’ homes. Curbing the production of these lethal weapons is among my top priorities and it should be for all levels of government. As a Daily News editorial last week noted, the U.S. Supreme Court has an opportunity to save lives by upholding the legality of the federal regulation restricting the sale of un-serialized “ghost gun” components. At issue is whether kits or parts of an unassembled firearm can be classified as guns under federal law. My office filed an amicus curiae brief in this case so that these ghost guns can be regulated in the same manner as other firearms, which would mean that the parts possess serial numbers and that background checks are required for those who buy such parts. The proliferation of ghost guns is one of the most startling trends to appear in recent years. These guns have been used in homicides and in gang warfare. According to NYPD data, in 2020, ghost guns constituted less than 3% of all guns recovered at crime scenes citywide. By the end of 2023, 11% of all guns recovered at crime scenes were ghost guns, demonstrating the growing need to eradicate this threat. Seeing this trend, in 2021 I created the first Crimes Strategies & Intelligence Bureau (CSIB) in Queens, tasked with instituting a proactive, intelligence-based approach to crime prevention. My goal was clear: identify and interrupt crime trends before the public safety crisis emerges. To date, my office’s CSIB investigations have led to the recovery of more than 400 firearms, including 290 ghost guns; 1,040 high-capacity magazines; more than 50 silencers; more than a dozen machine gun conversion devices; 15 bulletproof vests; numerous 3D printers; more than 135,000 rounds of ammunition; and enough component parts to build an additional 311 ghost guns. As a result, Queens is leading all of New York City in the total number of successful investigations and ghost gun recoveries for the fourth year in a row, with 151 (or 45.6%) of the 331 ghost guns recovered citywide year to date. Many of our recent ghost gun investigations reveal that the people building these arsenals have expanded beyond drug runners and traffickers to people from a wide array of social, economic and professional backgrounds. Now, we’re seeing many defendants who are contending that this activity is a kind of “hobby.” We have prosecuted city workers, students, security guards, and a pharmacist, among others — some with criminal convictions, and others who had never previously been arrested or had so much as a traffic violation. In our conversations with defendants and their attorneys, we commonly hear that they never intended to sell or use their personally manufactured firearms. My response to that is simple. Possession of ghost guns is dangerous and it’s a criminal act. You will be held accountable. Hard stop. New York State law is clear and unequivocal: you cannot possess an un-serialized and/or unlicensed firearm regardless of whether you built it from component parts you ordered online, 3D printed it from plans downloaded from a website, or bought it directly from a manufacturer. It does not matter whether the individual intended to use the firearm or not. Each of our ghost gun defendants was primarily charged with possessing the illegal firearms because we seized these weapons before they could ever be used. Ghost guns are now much more easily made, and unlike a licensed gun owner, there are no background checks or restrictions to access these firearms, yet the constructed weapons are just as lethal. Far too often children are the victims of gun violence. My office has recovered hundreds of illegal ghost guns that were not properly secured in homes where children were present. A recent study found that more than 90% of guns used in accidental shooting deaths of children were left unlocked and loaded. Keeping our neighborhoods secure is a shared responsibility. I urge parents to remain vigilant about their children’s activity on the internet. Stay connected, stay engaged, and remind them of the very real dangers that firearms can present. No matter the outcome of the landmark Supreme Court case, my office will remain vigilant and enforce the laws of the state of New York to ensure that the residents of Queens are safe. There are myriad “hobbies” that can keep your hands from becoming idle — but I caution that building illegal firearms is not one that will be tolerated in this borough. Katz has served as the district attorney of Queens since 2020.