a ghost gun is a nearly untraceable firearm that can be made at home the number of these weapons found at crime scenes around the US has soared in recent years because they’re privately made they have no serial numbers that makes it nearly impossible for investigators to trace them generally Firearms manufactured by licensed companies must have serial numbers that allow investigators to trace guns linked to crimes back to the manufacturer the Firearms dealer and the original purchaser ghost guns however are made of parts that the owner can assemble together themselves the critical component in build an untraceable gun is what’s known as the lower receiver some ghost guns are sold in do-it-yourself kits and the receivers are typically made from metal or polymer types of ghost guns include semi-automatic handguns and rifles it is legal in the US to build a firearm for personal use until recently ghost gun kits were available online without background checks or age verification as police found more ghost guns at crime scenes the Biden Administration moved to add age requirements and background checks in 2022 the number of ghost guns has since declined somewhat