The possibility of people using 3-D printers, a new technology that so far is uncommon outside of research or prototype-fabrication facilities, to produce weapons raised eyebrows after the anarchic Texas group Defense Distributed posted a YouTube video in May of the "Liberator," a Star Wars-like plastic gun. Many fear that the guns could allow criminals or terrorists to evade metal detectors.
In the past, some city ordinances regarding firearms have been struck down because, in Pennsylvania, state law preempts cities when it comes to guns. But Johnson said that won't be a problem in this case.
"The prohibition that city ordinances can't overcome as it relates to state legislation is primarily ownership, transfer of a firearm. This goes to manufacturing," he said. "We've spoken with the Law Department. We believe that if there is a challenge in the court system, it will be something we'll be able to defeat."
The Philadelphia Police Department testified in support of the measure. Capt. Frank Healy, a PPD legal adviser, said, if passed, this could be the first municipal law in the country to explicitly ban 3-D printing of guns.
The federal Department of Justice is looking into ways to regulate the practice, and New York lawmakers are exploring the issue as well.
Council members Johnson, Curtis Jones Jr., Jannie Blackwell and Denny O'Brien voted in favor of the bill.
On Twitter: @SeanWalshDN