Democratic senator points to Trump Jr as next 'potential target' for Mueller
Donald Trump, Jr. speaking with supporters of his father at a campaign rally at the Sun Devil Fitness Center at Arizona State University. (Photo by Gage Skidmore.)

On Thursday, Sen. Richard Blumenthal (D-CT) said that the mystery behind Donald Trump Jr. phone calls only "deepened" after an investigation confirmed that the phone call was not made to President Donald Trump, but to business associates.

"I was in the room when Donald Trump Jr. appeared. He could not recall whom he called. The communication between father and son here has yet to be fully explained," Blumenthal told CNN host Wolf Blitzer.

After the indictment of Trump's longtime confidant Roger Stone, Blitzer asked who he thinks would be indicated next in Special Counsel Robert Mueller's investigation.

"I think speculation here is inappropriate. Perhaps members of the president's family, or other members of his campaign team," Blumenthal said.

"Do you know of others who may have lied to your committee?" Blitzer said.

"I believe that there are serious questions about Donald Trump Jr. appearance before our committee," Blumenthal said.

"Are you suggesting Donald Trump Jr. lied to your committee under oath and potentially he could be charged?" Blitzer said.

"I'm suggesting there are serious questions. He needs to come back. He ought to be subpoenaed to come back. I asked to subpoena him. I think there's a possibility," he said.

"Do you think Robert Mueller and his team are thinking and considering indicting Donald Trump Jr?

"I would not be at all surprised if there is a consideration. He is a potential target. He may have lied before our committee," Blumenthal said.

He added, "I'm not suggesting that he is on the verge or that he will, in fact, ever indict Donald Trump Jr. But those responses that he gave to our committee certainly raise questions about his credibility."

Watch below via CNN.