Abe was Japan's longest-serving prime minister. He was 67.

Abe was shot at about 11:30 a.m. local time in Nara, east of Osaka while giving an election campaign speech on the street.

The bullet hit him on the right side of his neck, according to officials in Tokyo. He was rushed to the hospital first by ambulance, then by medical helicopter.

Abe was declared dead at 5:03 p.m. local time, according to the head of Nara Medical University.

Doctors told a news conference that the former prime minister succumbed to the injury that caused excessive bleeding and the bullet pierced deep enough to reach his heart.

Police arrested Tetsuya Yamagami, a Nara resident in his 40s, in relation to the shooting, according to NHK, citing police sources. The assailant used a handmade gun and did not try to escape and is being held for questioning at Nara Nishi police station, it added.

Abe belonged to a family of prime ministers

Abe was born to one of the top prominent political families of Japan on September 21, 1954, in Tokyo. Both his grandfather and great uncle had been prime ministers, and his father served as a former secretary-general of the right-leaning Liberal Democratic Party (LDP).

He went to Tokyo's Seiki University and the University of Southern California, where he studied politics. Initially, he took a position with Kobe Steel in 1979, and three years later, started working as an assistant to the Minister for Foreign Affairs.

Abe was first elected to Japan's House of Representatives in 1993, at age 38. He held various cabinet positions throughout the 2000s.

In 2003, he became secretary-general of the LDP, and four years later, was named the party's president and became prime minister of Japan.

Worsening health and a number of controversies hit during his first term and he stepped down as party leader and prime minister in 2007.

He was re-elected in 2012 but stepped down in 2020 citing ill health.

Japnese PM calls him a personal friend

Japanese Prime Minister Fumio Kishida paid his “deepest condolences” to former leader Shinzo Abe on Friday, saying he “was a personal friend, with whom I spent a lot of time”, CNN reported.

Speaking at a news conference on Friday, Kishida said he had “great respect for the legacy (Abe) left behind,” adding he had received a lot of advice from his predecessor and was grateful for his warm support.

Who would want to kill Abe? And why?

Shinzo Abe was a huge figure in Japanese public life and probably the most recognisable Japanese politician of the last three decades, says BBC's Rupert Wingfield-Hayes in a report from Japan.

The attacker, 41-year-old Tetsuya Yamagami, is a former member of the country's self-defence forces, the equivalent of an army.

Despite the presence of a team of security police with Abe, the gunman managed to get within a few metres of him where no checks or barriers were present.

From the pictures of the gun lying on the ground after the shooting, the gun seemed just two pieces of steel pipe joined together with black gaffer tape, and a handmade trigger.

The report said it looked like something fashioned from plans downloaded off the internet.

Gun laws in Japan are tough and it is extremely difficult to own one.

In order to possess a gun, one should not have a criminal record,  have mandatory training, and be psychologically evaluated. Additionally, the authorities conduct extensive background checks including police interviewing neighbours.

Consequently, gun crimes are nearly absent, with an average rate of fewer than 10 each year. In 2017, there were just three, said the report.

With these facts, people are shocked by the death of a prominent leader in gun violence. BBC's Rupert Wingfield-Hayes writes that the attention has been focused on the gunman and the weapon he used.

Because of low crime rates, security in Japan is relaxed. Politicians, including top leaders, give speeches standing on street corners and even shake hands with storekeepers and people passing by.

Apparently, thin and relaxed security allowed Abe's attacker to shoot him from a close range.

The investigators are trying to ascertain if it was a planned political attack, or the act of a fantasist, someone who wanted to get famous by shooting someone of acclaim.

Ninety investigators are dedicated to the case, police said, reported CNN.

Local media outlets reported that Yamagami told police he was "dissatisfied with former Prime Minister Abe and aimed to kill him" but did not hold a "grudge against the former Prime Minister's political beliefs", according to a BBC report.

Tetsuya told police he holds hatred towards a certain group, which he thought Abe was linked to, CNN reported.

As police searched Yamagami's house, several possible explosive devices were found, and NHK said bomb disposal technicians prepared to conduct a controlled explosion on the premises.