STORY: Donald Trump has been indicted by a federal grand jury for retaining classified government documents and obstruction of justice, according to a lawyer for the former U.S. president and another source familiar with the matter.

"Well, if you lied to federal prosecutors, it doesn't matter if you're the former president of the United States. And that's actually, while this is a serious and somber occasion, it's actually an example of one of the positives of America, accountability to the rule of law, even at the highest levels," said Sample, a professor of constitutional law at Hofstra University.

The law professor added that Trump can still run for president.

"We live in a country where in the United States, rightly or wrongly, a convicted felon, even if he's convicted, can be elected president. He could even, in theory, serve as president while incarcerated."