Colorado Congressmen Ken Buck, Joe Neguse Grill Robert Mueller

WASHINGTON (CBS4) - Former Special Counsel Robert Mueller spent hours on Capitol Hill on Wednesday answering questions from dozens of Congress members about the investigation into Russian tampering in the 2016 presidential election. Two of those posing questions were Rep. Ken Buck and Rep. Joe Neguse, two Coloradans who both serve on the House Judiciary Committee.

Buck, a Republican who represents Colorado's 4th Congressional District and a former prosecutor, he brought up questions about whether there was enough evidence to prosecute President Donald Trump for obstruction of justice.

"Was there significant evidence to convict President Trump or anyone else with obstruction of justice?" Buck asked.

"We did not make that calculation," Mueller said.

"How could you not have made the calculation?" Buck asked.

"Because the OLC opinion, office of general counsel, indicates that we cannot indict a sitting president. So one of the tools that a prosecutor would use is not there."

"But ... you made the decision on the Russian interference. You couldn't have indicted the president on that and you made the decision on that. But when it came to obstruction, you threw a bunch of stuff up against the wall to see what would stick. And that is fundamentally unfair," Buck said.

"I would not agree to that categorization at all," Mueller said.

The hearing did get testy at times with members of the committee raising their voices over a number of issues, including whether Mueller made political statements in his report.

Democrat Joe Neguse, who represents Colorado's 2nd Congressional District, questioned Mueller about a meeting that took place at Trump Tower.

"Your investigation found that Hope Hicks, the president's communications direction, in June of 2017 was shown emails that set up the Trump Tower meeting and she told your office that she was quote 'shocked' by the emails because they looked 'really bad'? True?"

Mueller responded to Negues with short, one word answers and didn't elaborate on any of them.

Democrats had hoped to use the hearings to show Trump had indeed obstructed justice, saying several times no one is above the law.

Republicans have repeatedly criticized Mueller for not making a determination while also not exonerating the president, arguing he should have made a determination one way or the other.