The country mourned Japan’s longest-serving prime minister and well-wishers gathered to pay their respects, with senior politicians dressed in black arriving at Abe’s Tokyo residence on Saturday to offer their condolences. But candidates also continued to campaign for Sunday’s upper house election, with the prime minister, Fumio Kishida, saying: “We must never allow violence to suppress speech during elections, which are the foundation of democracy”. The killing of Japan’s best-known politician has shocked the country and sent shockwaves around the world, especially given Japan’s low levels of violent crime and strict gun laws. Police are still gathering details about the man who opened fire at close range on Friday, but the 41-year-old named as Tetsuya Yamaguchi confessed to killing the former prime minister, motivated by the belief that Abe was linked to an unspecified organization. The police chief in the Nara region where Abe was killed admitted on Saturday that there were “undeniable” flaws in the former leader’s security. “I think it is undeniable that there were problems with the guarding and security measures for former Prime Minister Abe,” Tomoaki Onizuka said, pledging a “thorough investigation.” “In all the years since I became a police officer in 1995 … there is no greater remorse, no greater sorrow than this,” he said. Early Saturday afternoon, Abe’s body arrived at his home, where mourners gathered to offer prayers and flowers. One, Tetsuya Hamada, said: “I’m surprised that things like this are still happening in Japan. It saddens me. How could this have happened in broad daylight?’ Japan’s upper house election will go ahead as planned on Sunday, and Kishida called on supporters to “support us until the end”. However, Abe’s death has cast a long shadow and at the scene of his assassination, 52-year-old Kayoko Ueda wiped away tears and described herself as “distraught”. “I couldn’t believe something like this could happen in Japan,” he said. Yamagami’s motives remain unclear, with police so far refusing to identify the organization with which Abe was believed to have ties. They are investigating claims Yamagami served in the Japanese navy and said he appeared to have used a homemade weapon. National broadcaster NHK said it described months of planning for the attack, including an initial plan involving explosives that was later dropped in favor of weapons. Subscribe to First Edition, our free daily newsletter – every morning at 7am. BST Security at local campaign events in Japan can be relatively lax, but given Abe’s profile, questions have been raised about whether measures to protect him were too lax. Footage of the attack showed Yamaguchi was able to approach Abe from behind without being intercepted and pull a gun from a bag. He appeared to fire two shots, each of which produced a cloud of smoke. Doctors who treated Abe said he suffered multiple wounds to his neck and the internal damage from the gunshot went as deep as his heart. He died of blood loss, despite massive transfusions. International reaction to Abe’s death was swift and strong, with US President Joe Biden saying he was “surprised, outraged and deeply saddened” and ordering flags at half-mast on US government buildings. Chinese President Xi Jinping said he was “deeply saddened” by the killing, which South Korea’s president called an “unacceptable act”. Local media reported that a wake will be held on Monday evening and a funeral on Tuesday for close family and associates.