According to The Guardian and various other sources, Abe was making a speech on behalf of a Liberal Democratic Party candidate ahead of the upcoming upper house elections at the time of the shooting. Abe was shot up to three times from behind with a shotgun. Abe was transported to a local hospital with a chest wound, reported to have no vital signs at the hospital as of 12:07 JST. Tetsuya Yamagami, the assailant who is a 42-year-old male from Nara City, was immediately apprehended by police, according to Japanese news media.
From the pics at link, it appears that Abe’s son may have been at his side. If so, the son witnessed the assassination of his father. Hope I’m wrong, but scroll down and look at pic in link.