A soaring number of “ghost guns” are being used in crimes in the U.S., according to a landmark new report from the Bureau of Alcohol, Tobacco, Firearms and Explosives.

The number of suspected ghost guns recovered by law enforcement and submitted to the bureau for tracing increased by more than 1,000% between 2017 and 2021. The number more than doubled from 2020 to 2021.

“It’s really reflective of what happens when an industry intentionally circumvents the law to sell unregulated and serialized firearms,” said Tanya Schardt, senior counsel at Brady: United Against Gun Violence, a gun safety advocacy group. “All Americans have really suffered as a result.”

What are ghost guns?

Also known as “privately made firearms,” homemade guns are often assembled from kits purchased online or 3D-printed. They don’t require the typical background checks for purchase and do not have serial numbers.

Police recovered and traced more than 19,000 ghost guns in 2021

The data shows an “exponential rise” in suspected ghost guns recovered and traced by law enforcement, Schardt said. But she noted the numbers don’t capture the full picture since most ghost guns are not sent to the bureau for tracing.