The police chief overseeing security when Japan’s ex-prime minister Shinzoe Abe was assassinated has admitted a “grave sense of responsibility” for failures.

Nara prefectorial police chief Tomoaki Onizuka said the security arrangements had not been prepared until the day before and had been flawed.

“We can’t deny that there were problems with the security plan given how things ended,” said Nara prefectorial police chief Tomoaki Onizuka at a news conference.

“I feel a grave sense of responsibility.”

Nara prefectorial police chief Tomoaki Onizuka bows during a media conference where he admitted flaws in security. Photo: AAP

Tetsuya Yamagami, an unemployed 41-year-old, was identified as the suspect on suspicion of murder on Friday.

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 40cm weapon wrapped with black tape.

He was tackled by police at the scene.

The police admission comes as more details have emerged about the man who used a homemade gun to killing Mr Abe after months of stalking and plotting.

Media reports say the suspect believed Mr Abe was linked to a religious group that he blamed for his mother’s financial ruin.

Yamagami was a loner who did not reply when spoken to, neighbours told Reuters.

He believed Mr 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.

The suspect, holding a homemade gun, is tackled by security. Photo: AAP

Nara police declined to comment on the details reported by Japanese media of Yamagami’s motive or preparation.

Media have not named the religious group he was reportedly upset with.
Yamagami built the weapon from parts bought online, spending months plotting the attack, even attending other Abe campaign events, including one a day earlier some 200km 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.

Yamagami lived on the eighth floor of a building of small flats. One of his neighbours, a 69-year-old woman who lived a floor below him, saw him three days before Abe’s assassination.

“I said hello but he ignored me. He was just looking down at the ground to the side not wearing a mask. He seemed nervous,” the woman, who gave only her surname Nakayama, told Reuters.

“It was like I was invisible. He seemed like something was bothering him.”

A makeshift memorial outside Yamato-Saidaiji Station where Shinzo Abe was shot. Photo: Getty

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.

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.