MOST STATES AND DC HAVE SEEN CRIMINAL CASES INVOLVING LEGAL, VIRTUALLY UNTRACEABLE "GHOST GUNS," "60 MINUTES" FINDS, AS SALES OF THE HOMEMADE WEAPONS RISE IN THE PANDEMIC

"Ghost guns," virtually untraceable weapons that can be made at home using legally purchased parts, have turned up in criminal cases in most of the country, a 60 MINUTES report reveals. Sales of those parts are on the rise, along with traditional firearms, across the U.S. during the pandemic. Bill Whitaker and his team's year-and-a-half investigation will be broadcast on 60 MINUTES Sunday, May 10 (7:00-8:00 PM, ET/PT) on the CBS Television Network.

60 MINUTES spoke to local and national law enforcement and found the majority of states and the nation's capital have seen cases involving ghost guns. The authorities say the guns, made with unfinished parts that under federal law don't require serial numbers or a background check to purchase, have become a weapon of choice among criminals and those legally prevented from owning guns. Ghost guns have turned up in mass shootings, police shootouts, gang activity and cases involving terrorism and white supremacy.

Many ghost guns can be put together using simple tools - online videos can show you how. 60 MINUTES producers were able to order a kit with everything someone would need to build their own 9mm handgun. Thomas Chittum, assistant director of field operations for the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), says the ease of purchasing these parts "makes it challenging to keep it out of the hands of people who are not allowed to possess firearms." How many of these untraceable weapons are on the streets? "I have no idea," Chittum tells Whitaker.

A ghost gun was used to murder Gracie Muehlberger, 15. She died in a high school shooting in Santa Clarita, Calif., six months ago. Nathaniel Berhow, a 16-year-old classmate, used a ghost gun to kill her and Dominic Blackwell and to wound three other students before turning it on himself. Law enforcement believes the weapon had originally belonged to Berhow's father, who'd turned to ghost guns after having his own firearms confiscated following a psychiatric detention.

"Up to that day, I never heard the term ghost gun. So I didn't even know what that was," says Gracie's father, Bryan Muehlberger. "I'm not against owning guns, but I also believe strongly that this is a serious problem that's occurring that no one knew about. So I feel like something needs to be done, It's just - it's become too easy."

A few states, including California, have moved to restrict the sale of ghost gun parts, but that's not the solution, says Los Angeles County Sheriff Alex Villanueva, who was on the scene the day Gracie was murdered. "You can just defeat it by going to another state."

Villanueva says the number of ghost guns turning up in LA County Sheriff investigations has gone up 50 percent over the past year.

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