Itaru Nakamura, commissioner general of the National Police Agency (NPA), made his announcement following the release of a review of security at the time Abe was fatally shot while delivering a street speech during an election campaign.
"The National Police Agency believes it is necessary to steadily implement measures based on the new security requirements under a new system to prevent such an incident from happening again," Nakamura told a press conference.
"Today, I conveyed to the National Public Safety Commission my intention to resign, in an effort to revamp personnel affairs," he said, with his resignation likely to be approved at a Cabinet meeting on Friday.
The results of the review in the wake of Abe’s assassination revealed the police’s failure to protect the former leader.
It detailed serious flaws in security plans, insufficient command and communication at the scene, and a failure to notice the gunman approaching Abe.
Abe delivered a stump speech in the western city of Nara on July 8 ahead of an upper house election. A lone assailant was able to approach Abe with a homemade gun and fire two shots from behind Abe with his security details unable to respond in time to prevent or limit the attack.
At the time of the shooting, one policeman from the Tokyo metropolitan police force and a few local police officers were close to Abe at the time of the shooting.
Numerous security experts here have attested the attack could have been prevented or at least not resulted in Abe being fatally wounded, had his security details acted in unison to both suppress the attacker whilst simultaneously shielding and moving Abe out of the line of fire.
According to the NPA, one of the biggest errors in security measures at the time of the shooting involved a police officer from Nara changing his position during Abe’s speech.
He moved from outside a small area of guardrails surrounding Abe where he was covering the former leader’s back, to inside the rails where the policeman then turned his back to the crowd, the agency said.
The local police officer did not inform his team leader or other officers of his movements, said the NPA.
On Thursday, the head of the Nara Prefectural Police, Tomoaki Onizuka, also announced his intention to step down.