Japanese police said Wednesday they have found a number of what they believe are bullet marks on a building near the site of former Prime Minister Shinzo Abe’s assassination last week in western Japan, apparently from the first shot fired from a suspect’s powerful homemade gun that narrowly missed Abe.

Abe, the country’s longest-serving prime minister who remained influential even after stepping down two years ago for health reasons, was gunned down Friday during a campaign speech near a crowded train station in Nara.

A bullet from a second shot, fired seconds after the first from behind Abe, fatally struck him just as he turned around, apparently in reaction to the initial explosive sound.

The suspect, Tetsuya Yamagami, 41, was arrested on the spot Friday. He can be detained for police investigation for up to three weeks before prosecutors decide whether to formally charge him with murder.