WASHINGTON — Presidential election campaigning revved back up Tuesday, with former President Donald Trump heading to Michigan and Vice President Kamala Harris answering questions at a forum for Black journalists in Pennsylvania — all while authorities investigate the second apparent assassination attempt against Trump that’s roiled the race.

Investigators were examining how a felon obtained the semiautomatic rifle that he aimed onto Trump’s golf course, after waiting there for almost 12 hours before being arrested Sunday.

Federal investigators are looking into the motives of the suspect, Ryan Wesley Routh, 58, and how he learned of Trump’s golf outing Sunday. A review of public records and Routh’s writings depict a crusader who “acted like he had some sort of mental health issues,” according to one police officer who had a run-in with him.

Trump was scheduled to hold a town hall in Flint, Michigan, and has appearances later in the week in New York, Washington and North Carolina. Harris participated in a Philadelphia gathering of the National Association of Black Journalists. She skipped the group’s recent gathering in Chicago, while an appearance there by Trump sparked an uproar when he questioned the vice president’s racial identity.

Harris has her own stops in Washington, as well as Michigan and Wisconsin, planned in coming days, with both sides zeroing in on the industrial Midwest and Pennsylvania and North Carolina — all battleground areas that could swing an election expected to be exceedingly close.

Harris said in an interview recorded Monday that she was “briefed immediately after” the apparent assassination attempt and that she was grateful Trump was OK. Speaking with a Spanish-language radio host Chiquibaby, Harris echoed her past sentiments about the attack, condemning “violence of any kind.”

“We have to have civil dialogue, and be able to talk through our differences,” Harris said. “And violence has no place.”

The vice president also talked about her mother, the late Shyamala Gopalan, who was born in India, being an immigrant to the U.S.

She blamed Trump for helping to derail a bipartisan border security plan in Congress and detailed her plans to use tax incentives to encourage first-time home purchases and combat grocery “price gouging” to help tame inflation.

Trump has claimed, without evidence, that months of criticisms against him by Harris and President Joe Biden inspired the latest attack. That’s despite the former president’s own long history of inflammatory campaign rhetoric and advocacy for jailing or prosecuting his political enemies.

Both Biden and Harris have so far avoided politics in reacting to the attack. Biden has called on Congress to increase funding to the Secret Service.

That attack came barely two months after Trump was wounded during a rally in Pennsylvania. In fundraising emails, he’s implored supporters, “Fear not.”

During an interview Monday evening on the X social media platform to launch his family’s cryptocurrency venture, World Liberty Financial, Trump also gave his first public comments about his experience Sunday, saying he and a friend playing golf “heard shots being fired in the air, and I guess probably four or five.”

“I would have loved to have sank that last putt,” Trump said. He credited the Secret Service agent who spotted the barrel of a rifle and began firing toward it as well as law enforcement and a civilian who he said helped track down the suspect.

Trump did not discuss specifics about World Liberty Financial on Monday or how it would work, pivoting from questions about cryptocurrency to talking about artificial intelligence or other topics.

Beside him were his collaborators, including a family friend; Trump’s two oldest sons, Donald Trump Jr. and Eric Trump; and two little-known crypto entrepreneurs, Chase Herro and Zachary Folkman, with no experience running a high-profile business.

Trump has promoted the venture since August, but its exact purpose remains unclear. No official launch date has been set.

It’s highly unusual for a presidential candidate to embark on a new business just weeks before Election Day, and even rarer for one to aggressively promote a venture designed to benefit himself and his family.

Experts have said a presidential candidate launching a business venture in the midst of a campaign could create ethical conflicts.

The New York Times contributed.