A man indicted for killing former Japanese Prime Minister Shinzo Abe in 2022 pleaded guilty to the charge on Tuesday, the first day of his trial which began three years after the shooting.

Axar.az reports, citing Kyodo, Tetsuya Yamagami, 45, is accused of murdering Abe, the country's longest-serving postwar prime minister, with a homemade firearm during an election stump speech in western Japan. The Nara District Court will hold a series of hearings before ruling on the case in January.

Yamagami has told investigators that he committed the crime due to a grudge he held against the Unification Church over the financial ruin caused to his family as a result of massive donations -- likely some 100 million yen ($660,000) -- that his mother made to the group.

Abe was targeted as his grandfather, former Prime Minister Nobusuke Kishi, helped introduce the group, formed in 1954 by a staunch anti-communist in South Korea, to Japan, according to investigative sources.

The high-profile case prompted 727 people to line up Tuesday morning in hopes of securing one of the 32 public seats in the courtroom. Tickets were distributed via lottery.

The killing brought intense attention to the ties between the controversial religious group and members of the ruling Liberal Democratic Party, which Abe formerly led.