Man busted for possessing handguns made with 3-D printer

May 09, 2014


A man who has admitted to making handguns with a three-dimensional printer has been arrested on suspicion of violating the Swords and Firearms Control Law, in Japan’s first criminal case involving guns made with a 3-D printer.

Kanagawa prefectural police apprehended Yoshitomo Imura, 27, a staff member of the Shonan Institute of Technology in Fujisawa, Kanagawa Prefecture, on May 8 for possessing two plastic guns capable of killing or injuring people. The suspect produced the guns based on blueprints downloaded from a U.S.-based website, the police said.

According to the police, Imura, a resident of Kawasaki, also in the prefecture, has told them, “I made the guns by myself by repeatedly making improvements to the blueprint.” Therefore, police are also investigating him on suspicion of violating the Ordnance Manufacturing Law.

Imura also posted his blueprints on the Internet, and has repeatedly said on Twitter that he will spread the blueprints throughout Japan.

Police said the two self-produced guns were found in Imura’s home April 12 during an investigation.

“I had thought guns are necessary for physically weak people to protect themselves. In Japan, it is not allowed to possess guns (by buying them). So, I thought that I will make guns by myself,” Imura said, according to the police report.

Imura’s father, who lives with the suspect, told The Asahi Shimbun: “(My son) purchased a 3-D printer about half a year ago. When he saw a U.S. TV program that showed a university student making a gun, he said, ‘I can make a better one.’ ”

The prefectural police seized five self-produced plastic guns at Imura’s house. After testing the guns, two were found to be powerful enough to kill or injure people. One had the power for the bullets to penetrate 11 veneer boards, each measuring 2.5 millimeters thick, while another could fire a projectile that could penetrate 15. Both guns had at least five times more power than necessary to kill or cause injury. Police judged that the two weapons are subject to the Swords and Firearms Control Law.


When 3-D printers were developed in the 1980s, they were used to make samples of industrial products or to manufacture parts. In recent years, however, they have been used for a wider range of products, including 3-D models of organs and bones for surgery practice and fuel nozzles of jet engines.

As 3-D printer technology improved, prices for the machines dropped rapidly, making them relatively affordable. But this ready accessibility has created concerns that 3-D printers could be used to commit criminal acts.

One possible crime is skimming, which steals information embedded in credit cards or other cards.

In March, Tokyo-based information security company Trend Micro Inc. reported that 3-D printers could possibly be used to manufacture machines for skimming.

Skimming machines, which look like terminals for point of sale (POS) systems at stores, have already been put on sale on the Internet by cybercrime groups. It is believed that some of those machines were made with 3-D printers.

It has been also advertised online that a factory in China can mass-produce such skimming machines using 3-D printing technology.

“The newest models (of 3-D printers) can manufacture products in the unit of 50 micrometers (one micrometer is one-thousandth of a millimeter),” said Nobuki Sakaguchi, president of Open Cube Inc., a domestic 3-D printer maker based in Yokohama.

The company is considering urging its customers not to use 3-D printers for illegal activities. However, Sakaguchi said, “Eventually, whether to use them for criminal acts or not depends on the ethics of individual customers.”

“If you use 3-D printers, you can make copies of other people’s keys without obtaining their permission and use them for theft. Changes in laws to prevent abuse of technology are lagging,” said Shinsho Ri, president of Nihon 3D Printer, an import agent based in Tokyo.

Meanwhile, an official of the National Police Agency in charge of the issue, said, “It is not easy to regulate 3-D printers because doing so has a major impact on people’s lives.”

For the time being, therefore, police can only arrest violators based on current laws.

Masahiro Anzai, a professor of material engineering at Shibaura Institute of Technology, who has researched 3-D printers for about 20 years, said: “It is regrettable that technologies for the advancement of manufacturing are used in such ways. How we control the ways of using 3-D printers is a difficult problem in current times when people can easily obtain blueprints on the Internet.”

(This article was compiled from reports by Takahiro Takenouchi, Naoki Kuroishi, Orie Yoshihama and Yusuke Saito.)

  • 1
submit to reddit
The Asahi Shimbun

The Asahi Shimbun

  • The Asahi Shimbun
  • Skimming machines that look like terminals for POS systems are believed to be manufactured with 3-D printers. (Provided by Trend Micro Inc.)
  • A fake card insertion slot for an automated teller machine. It is believed to have been made with a 3-D printer. (Provided by Trend Micro Inc.)

More AJW