Alarm raised over DIY firearms as Incheon shooting suspect says he watched gun-making videos on YouTube

A man who allegedly shot his son with a homemade firearm in Incheon on Sunday told police that he learned how to build weapons from YouTube, sparking renewed alarm over the spread of do-it-yourself firearms and the challenge of regulating them.

A bullet used in the Incheon homemade firearm murder case [YONHAP]

A man who allegedly shot his son with a homemade firearm in Incheon on Sunday told police that he learned how to build weapons from YouTube, sparking renewed alarm over the spread of do-it-yourself firearms and the growing challenge of regulating them.

The 62-year-old man had built the firearm by modifying steel pipes. Early Monday morning, police discovered another homemade device at the man’s residence in Dobong District, northern Seoul. The homemade bomb, set to detonate at noon on Monday, was removed and defused by officers at around 4:17 a.m. the same day.

Police believe the man constructed the bomb at home using flammable materials.

Homemade firearms and explosives have increasingly figured in violent incidents in Korea and abroad, raising concerns about public safety and the limits of current regulations.

A simple internet search in English returns hundreds of instructional videos showing how to build makeshift guns — from rudimentary models made of cardboard to nearly functional metal handguns — often under the premise that they are easy to build at home.

Videos related to homemade firearms in an internet search [SCREEN CAPTURE]

The recent shooting was the first fatal incident involving a homemade gun in Korea since 2016, when then-46-year-old Seong Byung-dae murdered police inspector Kim Chang-ho in Gangbuk District, northern Seoul.

Seong told police he had learned about explosives online and purchased materials near Cheonggye Stream and in the Euljiro area in central Seoul.

Similar incidents have drawn scrutiny globally. Former Japanese Prime Minister Shinzo Abe was assassinated with a homemade firearm in 2022. Last year, UnitedHealth Group CEO Brian Thompson in the United States was killed by a 3-D printed gun.

Explosives have also surfaced in recent domestic crimes.

In August 2024, a man in his 70s detonated a homemade device in a dental clinic in Gwangju over a treatment dispute. In 2020, a man in his 20s caused an explosion while attempting to confront a woman he had been stalking.

Experts warn that homemade weapons, combined with individual grievances or extremist ideologies, could lead to more so-called "lone wolf" acts — with individuals acting alone based on personal grievances.

“If distorted political beliefs are added to homemade weapons, we could see more lone wolves,” said Lee Woong-hyuk, a professor of police studies at Konkuk University. “We need to go beyond just cracking down on illegal weapons and look at identifying socially disconnected individuals as part of prevention.”

The father’s use of YouTube and homemade materials reflects a broader concern over 3-D printing and non-metal weapons, which are difficult for authorities to detect.

A police line is attached outside the residence of the suspect who shot his son with a homemade firearm in Incheon on July 21. [YONHAP]

“Korea regulates finished firearms, but there is little oversight of components or blueprints used in early assembly stages,” said Lee Man-jong, honorary professor at Howon University and chairman of the Korea Association of Terrorism Studies. “We need clearer rules for non-gunpowder launch mechanisms and better controls over illegal information online.”

Park Sang-jin, chief of the Incheon Yeonsu Police Precinct, said the man personally cut the steel pipes at a workshop and assembled the weapon at home.

“He also studied and constructed the explosive device before leaving his house,” Park said on Monday.

Yoo Jae-seong, acting commissioner general of the Korean National Police Agency, said the agency would "assess the investigation's findings to determine if changes to laws on homemade weapons are necessary."

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff. BY IM SOUNG-BIN [paik.jihwan@joongang.co.kr]