A recent request from a patron of Millburn (N.J.) Free Public Library (MFPL) was a first for the library—and it left the reference librarian unnerved. The patron wanted to use the facility’s 3D printer to create a part for an AR-15 rifle, according to Susan Jaffe Pober, the library’s head of information services.

The incident and the recent efforts by the Texas-based nonprofit Defense Distributed to publish blueprints for manufacturing 3D-printed guns has libraries across the country working to establish policies to block individuals from printing the weapons.

On July 31, US District Court Judge Robert Lasnik issued a temporary restraining order to block Defense Distributed from publishing the 3D-printed gun instructions online, but the plans could eventually be made public and already are available on the dark corners of the internet.

When MFPL’s librarian told the patron that printing weapons is against the library’s policy, he demanded to see it, Pober says.

“[My colleague] showed him our policy, and in addition to it being against our policy, we have a three-hour maximum” for any particular print job, Pober says. “His would have taken much longer than that.”

Frustrated with the response, the patron told the librarian he would go to another library and get it done, according to Pober.

“The reference librarian was shaken up; she kept her calm, but she was not expecting that,” Pober says. “It’s scary when you think people will be able to do this.”

Pober says MFPL’s board had the foresight in 2015 to prevent, among other things, the printing of “objects that are unsafe, harmful, dangerous, or pose an immediate threat to the safety and well-being of others.”

The American Library Association (ALA) has drafted a resource for libraries to develop policies and best practices regarding the use of their 3D printers.

Deborah Caldwell-Stone, deputy director of ALA’s Office for Intellectual Freedom, says just because the instructions are or might be available online does not mean a patron has the right to use library resources to print them.

ALA’s draft policy states that a possible settlement agreement on the Defense Distributed case “is not binding on libraries and does not create a right to use those plans to create guns on library 3D printers in violation of library policy or in violation of the applicable law regulating the manufacture or distribution of guns in the United States, such as the law that makes it illegal to create or assist in the creation of a gun that is undetectable by X-ray machines or metal detectors.”

“We wanted to be prepared in case these incidents arose,” Caldwell-Stone says. She adds that having such policies in place grants the library the right to review and reject any print requests, although it might not be a problem for some libraries that do not carry the type of filament needed to produce such a part.

Following the MFPL incident, the resource guide released by ALA is a call to libraries to evaluate their policies, she says.

Pober says she first wrote about the incident on a librarian Facebook group. The post prompted hundreds of responses from librarians across the country, which took her by surprise.

“The response was way beyond what I thought [it would be],” she says, adding that the incident has alerted library staff to be more vigilant “about making sure we know what is being printed.”