Suspect in Shooting of Japan’s Abe Thought to Have Trained in Rifle Use

Police have detained Tetsuya Yamagami, a 41-year-old resident of Nara, on suspicion of the attack. On Friday, they said he told them he targeted Mr. Abe because he believed the former prime minister had links to a group that Mr. Yamagami held a grudge against.

National broadcaster NHK reported that Mr. Yamagami said his mother had run into personal problems after giving too much money to a religious organization. The police declined to provide further details of Mr. Yamagami’s testimony.

“We’re currently questioning the suspect to find out what steps he took, what motivated him, and his background. He’s been confessing in an indifferent fashion,” Nara Prefecture Police Chief Tomoaki Onizuka said in a press conference.

Mr. Yamagami couldn’t be reached for comment and it wasn’t known if he had a lawyer. The police have said he told them he fired shots at Mr. Abe.

Investigators are looking into how Mr. Yamagami possessed an apparent homemade gun, as well as other improvised weapons found in his apartment. Gun ownership is highly restricted in Japan and generally only allowed for hunting and sports shooting.

A public affairs officer at the Maritime Self-Defense Force, Japan’s navy, said a man with the same name and birth date as Mr. Yamagami served on a destroyer as part of a three-year stint in the service through 2005.

During his training period, the person would have learned the basics of rifle shooting and maintenance, including how to take the weapon apart, the official said. Members of the military also receive refresher training in gun use once a year.

The person belonged to a unit that handled weapons on the destroyer, the official said.

Mr. Abe was killed while campaigning for the ruling Liberal Democratic Party for national elections scheduled for Sunday. Candidates and senior-party members from across the political spectrum continued to campaign a day after the attack, some with increased security.

A wake will be held for Mr. Abe on Monday, followed by a funeral Tuesday, according to his office.

Tributes to Mr. Abe continued to flow on Saturday. Chinese President Xi Jinping sent a message to Japanese Prime Minister Fumio Kishida in which he said Mr. Abe made valuable contributions to the improvement of China-Japan relations, according to Chinese state media.

In Taiwan, President Tsai Ing-wen ordered that all flags at government institutions and schools be lowered at half mast for a day on Monday in honor of Mr. Abe.

Write to Alastair Gale at alastair.gale@wsj.com, Chieko Tsuneoka at chieko.Tsuneoka@dowjones.com and Miho Inada at miho.inada@wsj.com