Tokyo(CNN) Police in Japan have launched a murder investigation into the assassination of former Japanese prime minister Shinzo Abe -- but little is known about the suspect who was arrested at the scene of the fatal shooting on Friday.
Abe, 67, was pronounced dead by doctors at the Nara Medical University Hospital, at 5:03 p.m local time on Friday, just over five hours after being shot while delivering a campaign speech in front of a small crowd on a street.
Tetsuya Yamagami, 41, has admitted to shooting Abe, Nara Nishi police said during a news conference on Friday.
He was taken to the Nara District Prosecutor's Office on Sunday morning, and is being investigated as a "suspect for murder," according to police.
Yamagami, who is unemployed, told investigators he holds hatred toward a certain group that he thought Abe was linked to, Nara Nishi police said.
Investigators have said he targeted Abe due to the belief that his the former prime minister's grandfather expanded that group, Japanese public broadcaster NHK reported on Monday.
"I thought that former Prime Minister Nobusuke Kishi contributed to the expansion of the group, and I thought about killing his grandson, former Prime Minister Abe," Yamagami told investigators, according to NHK.
Police have not named the group, telling CNN they could not provide any information. CNN has not been able to independently confirm what group the suspect was referring to.
NHK and Kyodo News Agency have also reported that Yamagami said his mother was involved with the group, citing police.
The suspect's mother was a member of the Family Federation for World Peace and Unification, widely known as the Unification Church, said Tomihiro Tanaka, the church's Japan office chairman, in a statement on Monday.
The suspect was never a member of the church, while his mother has been a member who attended church events about once a month, the statement said. Tanaka added that the organization will cooperate with investigators if asked to do so.
CNN has not been able to locate her for comment or determine whether she has legal representation to confirm her alleged affiliation with the group.
Yamagami was described as a "totally normal" and seemingly "earnest" person by at least two people who had interacted with him, Kyodo News also reported.
He was hired through a dispatch agency in October 2020 to work at the freight department of a factory in Kyoto prefecture, the agency reported, citing an unnamed "former senior colleague".
The former colleague characterized Yamagami as someone who kept to himself.
"If it was work talk, he would respond, but he didn't go into his private life. He seemed mild-mannered," the former colleague said, according to Kyodo News. The former colleague added that Yamagami would "eat lunch alone in his car" and that "conversations with him never strayed beyond the topic at hand."
The former colleague said there had been no issues with Yamagami for the first six months of his employment, until he started to exhibit "gradual neglect" of work practices, according to Kyodo News Agency.
In March, Yamagami started taking "unauthorized time off" and spoke of "heart issues" and other physical problems, despite having no previous issues with punctuality or attendance. His employment ended on May 15, the agency reported.
An unnamed employee at the dispatch agency who interviewed Yamagami for the job described him as "totally normal," but added that he "didn't say much" and "had a slightly gloomy sense to him," according to the Kyodo News Agency.
The suspect used a homemade gun in the shooting, police said, and images from the scene showed what appeared to be a weapon with two cylindrical metal barrels wrapped in black tape. Authorities later confiscated several handmade pistol-like items from the suspect's apartment.
The weapon was a gun-like item that measured 40 centimeters (about 16 inches) long and 20 centimeters wide, police said.
Yamagami made multiple types of guns with iron pipes that were wrapped in adhesive tape, Japan's public broadcaster NHK reported, citing the police. The police found guns with three, five, and six iron pipes as barrels.
The suspect inserted bullets in his handmade gun, parts of which he had bought online, police said, according to NHK. Police believe the suspect used the strongest weapon he made in the assassination, NHK added.
Yamagami told police he watched YouTube videos to learn to make the weapon, and practiced shooting in the mountains days before the assassination, NHK reported Monday, citing 'investigators'.
Police found wooden boards with bullet holes in the suspect's vehicle, according to NHK.
On Monday, Nara police said Yamagami may have have carried out a "test shooting" of his homemade gun in the early hours of July 7, against the building of a "certain group" in Nara prefecture. The police refused to name the group.
Investigators said a vehicle believed to belong to the suspect was caught on security cameras close to the site of the alleged test shooting. The footage has not yet been made public.
The suspect told investigators he initially intended to kill Abe by using explosives, according to Japan's Public Broadcaster NHK.
Yamagami originally planned to assassinate Abe at an event in Okayama, a prefecture about three hours' drive from Nara, NHK reported.
"I was thinking about killing the former prime minister there (Okayama), but I saw that there were admission procedures at the entrance and I felt it would be difficult to get in", he told investigators, according to NHK.
Nara police told CNN on Saturday that surveillance footage showed Yamagami leaving the Yamato-Saidaiji Station in Nara on Friday after arriving by train.
At the time of the shooting, Abe was speaking in support of ruling Liberal Democratic Party (LDP) candidates ahead of Upper House elections on July 10. Despite resigning as Japan's prime minister in 2020 due to health reasons, Abe remained an influential figure in the country's political landscape and continued to campaign for the LDP.
Japan's National Police Agency said it will review security arrangements put in place before Friday's shooting, according to NHK. Security was being handled by Nara prefectural police, which drew up a security plan for the former prime minister while he was in the city.
The agency said several dozen officers and security personnel from the Tokyo Metropolitan police were on duty and had reportedly watched Abe from all sides during his speech, NHK said.