The man who killed Shinzo Abe believed the former Japanese leader was linked to a religious group he blamed for his mother's financial ruin and spent months planning the attack with a homemade gun, police told local media on Saturday.

Tetsuya Yamagami, an unemployed 41-year-old, identified as the suspect on suspicion of murder on Friday after a man was seen in videos repeatedly shown on Japanese television calmly approaching Japan's longest-serving prime minister from behind and firing.

Wiry and bespectacled with shaggy hair, the suspect was seen stepping into the road behind Abe, who was standing on a riser at an intersection, before unloading two shots from a 40-centimeter-long weapon wrapped with black tape. He was tackled by police at the scene.

Yamagami was a loner who did not reply when spoken to, neighbors told Reuters. He believed Abe had promoted a religious group that his mother went bankrupt donating to, Kyodo news agency said, citing investigative sources.

"My mother got wrapped up in a religious group, and I resented it," Kyodo and other domestic media quoted him as telling police. Nara police declined to comment on the details reported by Japanese media of Yamagami's motive or preparation.

The media has not named the religious group he was reportedly upset with.

Yamagami jury-rigged the weapon from parts bought online, spending months plotting the attack, even attending other Abe campaign events, including one a day earlier some 200 kilometers away, media said.

He had considered a bomb attack before opting for a gun, according to public broadcaster NHK.

The suspect told police he made guns by wrapping steel pipes together with tape, some of them with three, five or six pipes, with parts he bought online, NHK said.

Police found bullet holes in a sign attached to a campaign van near the site of the shooting and believe they were from Yamagami, police said on Saturday. Videos showed Abe turning toward the attacker after the first shot before crumpling to the ground after the second.

Navy gun experience

A person named Tetsuya Yamagami served in the Maritime Self-Defence Force from 2002 to 2005, a spokesman for Japan's navy said, declining to say whether this was the suspected killer, as media have reported.

This Yamagami joined a training unit in Sasebo, a major navy base in the southwest, and was assigned to a destroyer artillery section, the spokesperson said. He was later assigned to a training ship in Hiroshima.

"During their service, members of the Self-Defence Force train with live ammunition once a year. They also do breakdowns and maintenance of guns," a senior navy officer told Reuters.

"But as they are following orders when they do it, it's hard to believe they gain enough knowledge to be able to make guns," he said. Even army soldiers who serve "for a long time don't know how to make guns."

Some time after leaving the navy, Yamagami registered with a staffing company and, in late 2020, started work at a factory in Kyoto as a forklift operator, the Mainichi newspaper reported.

He had no problems until the middle of April, when he missed work without permission and then told his boss he wanted to quit, the newspaper said. He used up his holidays and finished on May 15.