Itaru Nakamura, commissioner general of Japan’s National Police Agency, told a news conference in the capital Tokyo that he “will step down to take responsibility for the assassination” of Abe.
The announcement came after the police released a report about their probe “into flaws in security for Abe,” Kyodo News reported.
"As we advance new security arrangements, it is a matter of course to go at it with a new lineup of people," Nakamura said.
Abe was shot during an election campaign speech in the western city of Nara last month. He succumbed to his injuries in a hospital hours later.
Tetsuya Yamagami, the 41-year-old attacker, had tested his weapon before he fatally shot the former Japanese premier.
Meanwhile, the Japanese government is mulling holding a state funeral for Abe, former leader of the ruling Liberal Democratic Party, despite opposition from several groups.
The planned event on Sept. 27 is expected to cost the Japanese government around 250 million yen ($1.8 million).
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