Donald Trump heads to convention as authorities investigate motive, security in assassination attempt

Trump and Biden call for unity and calm after an attempt on Trump's life during a tumultuous presidential campaign.

Former president Donald Trump called for unity and resilience on July 14 after an attempt on his life injected fresh uncertainty into an already tumultuous presidential campaign, while President Joe Biden implored Americans to “cool it down” in the final stretch and “resolve our differences at the ballot box.”

The opponents' statements followed an attack that shook the firmament of the American political system, causing at least a temporary detente in a heated presidential campaign expected to resume again in earnest amid the pageantry of the upcoming Republican National Convention.

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A full day after the shooting, the gunman's motive remained a mystery, with investigators saying they believe he acted alone before he was fatally shot by Secret Service agents. Mr. Biden ordered an independent security review of the attack, which killed a bystander, critically wounded two others and prompted questions about how a gunman was able to open fire from a rooftop near a Pennsylvania campaign rally. The FBI was investigating the shooting as a potential act of domestic terrorism.

Trump, the presumptive Republican presidential nominee, said the upper part of his right ear was pierced by a bullet. His aides said he was in “great spirits” and doing well. He arrived in Milwaukee on Sunday evening for the convention, which begins Monday. He told the Washington Examiner that he had rewritten his speech for the event to focus more on national unity than on the policies of Mr. Biden.

In a post Sunday on his social media site, Trump said: “In this moment, it is more important than ever that we stand United, and show our True Character as Americans, remaining Strong and Determined, and not allowing Evil to Win."

In a prime-time address, Mr. Biden urged the public to recommit to civil debate. “There is no place in America for this kind of violence — for any violence. Ever. Period. No exception," he said. "We can’t allow this violence to be normalized.”