U.S. Sen. Marco Rubio made clear before Wednesday's confirmation hearing for Rex Tillerson that he had concerns about the secretary of state nominee's position on Russia.
In his first chance to publicly question Tillerson, Rubio did not hold back.
First, Rubio tried to get Tillerson -- who called Russia a "danger" -- to agree to back sanctions on any Russian cyber attackers, something Rubio has proposed that Tillerson said he's not ready to do.
Then, Rubio escalated his questioning.
"Is Vladimir Putin a war criminal?" the Florida Republican asked the Exxon Mobil chief executive.
"I would not use that term," Tillerson responded.
Rubio cited Russian targeting of civilians in Aleppo, Syria, and bombings in Chechnya. Tillerson said he'd need more information to assign direct blame to the Russian president. Rubio cut him off.
"Mr. Tillerson, what's happened in Aleppo is in the public domain," he said. "There is so much information out there about what's happened in Aleppo.... It should not be hard to say that Vladimir Putin's military has conducted war crimes in Aleppo."
He called Tillerson's "inability" to call Russia's actions in Syria a war crime "discouraging."
Rubio then mentioned the Russian political dissidents and journalists who have died "under suspicious circumstances."
"Do you believe that Vladimir Putin and his cronies are responsible for ordering the murder of countless dissident journalists and political opponents?" he asked.
Tillerson: "I do not have sufficient information to make that claim." To advise future President Donald Trump, he added, it's important "that I deal with facts."
"None of this is classified, Mr. Tillerson," Rubio shot back. "These people are dead."
Said Tillerson: "I'm not disputing these people are dead."