As the U.S. continues to deal with an outbreak of mass shootings, police say that they are seeing more guns on the nation's streets than ever before.
U.S. gunmakers produced 11.3 million firearms in 2020, almost triple the 3.9 million produced 20 years ago, according to the Bureau of Alcohol, Tobacco, Firearms and Explosives.
John DeVito, the ATF's lead agent in New York City, told CBS News there are possibly 500 million firearms on the nation's streets right now, and another 18 to 20 million are added each year.
Officials say gun arrests are at a 28-year high in New York City, where every morning federal, state and local police meet to review strategy and seize illegal guns.
"We have the strongest gun laws in the country here, but the guns that are used in crime in New York City don't come from New York City," John Miller, the New York Police Department's intelligence chief, told CBS News.
The firearms are coming to New York City via the so-called Iron Pipeline — guns flowing from states with less restrictive laws to those with tougher laws, like New York. Law enforcement is also worried about the "Plastic Pipeline" — plasticordered online and built at home — which is harder to shut down.
During a recent raid in New York, police found a machine still carving out newparts to keep up with what law enforcement believes is currently an insatiable demand.
"We've seen them in basements. We've seen them in closets. You really don't need much room to put these guns together," Courtney Nilan, an NYPD inspector, told CBS News about the machines.
Miller said there's a "boom in ghost gun ordering."
"They're stockpiling," DeVito added.
Officials believe people are stockpiling ghost guns because manufacturers will have to stamp serial numbers on the homemade plastic guns beginning in August. The weapons don't currently have serial numbers, making them harder to trace if they are used in a crime. Increasingly, theare being used to commit crimes.
In New York City, there's been a more than 300% increase in ghost gun seizures so far this year compared with the same time period last year.