After citing Justice Department rules that he could not prosecute a sitting president, Mueller suggested that it's possible Trump can be charged after leaving the White House.
Here's the exchange between committee chairman Jerry Nadler and Mueller:
Nadler: "Is it correct that if you had concluded that the President committed the crime of obstruction, you could not publicly state that in your report or here today?"
Mueller: "The statement would be that you would not indict, and you would not indict because under the OLC opinion, excuse me, a sitting president cannot be indicted, it would be unconstitutional."
Nadler: "Under Department of Justice policy, the President could be prosecuted for obstruction of justice crimes after he leaves office, correct?"
Mueller: "True"
Note: Mueller did not, however, say if Trump should be prosecuted