Roger Stone 'has no defense': Ex-prosecutor predicts Trump pal will 'crack' after courthouse appearance

President Donald Trump's oldest political adviser, Roger Stone, plead not guilty to charges that he lied to investigators in relation to special prosecutor Robert Mueller's probe of Russian interference in the 2016 election.

On Friday, ex-federal prosecutor Paul Butler appeared on MSNBC with Ari Melber to explain the connections between Stone and Trump, and why he expects Roger Stone to flip.

Butler doesn't believe Trump's claims that he's not facing possible prosecution in the Stone case.

"I don't believe the president, in part because he wasn't coherent [in a New York Times interview] even yesterday. At first, he said that Rod Rosenstein had directly told him that he was not a target and then he said well, maybe he told my lawyers and the reporter asked, 'Well, when?' He couldn't remember," said Butler. "So there's a specific definition in the Department of Justice handbook which I looked at every day when I was a prosecutor. A target is someone who is about to be indicted. The specific phrase is 'when the prosecutor has substantial evidence linking him to the commission of a crime.' Almost certainly, in the southern district, Donald Trump, or Individual-A, as the prosecutor there likes to call him, is a target of that investigation."

Trump seems to be making denials with the understanding that he can't be indicted, Butler said.

"Maybe because he did do something wrong and he doesn't want the investigation to proceed?" Butler said. "This is a way of really embracing his formal status as president as a defense since he knows better than anybody else that the policy of the Department of Justice is that a sitting president can't be indicted."

The director of the documentary Get Me Roger Stone said the "cockroach" of American politics is not likely to go quietly.

Butler said he thinks Stone will flip given that he doesn't have much of a defense.

"But if he's looking at 10 years if he's convicted, at least, which means he will be 77," Butler said. "We'll see how much of a firebrand he is then. That's why I think he's probably going to make a deal."

"You think he could crack?" asked Melber.

"He doesn't have a defense, Ari. The defense to false statements is 'I told the truth.' Robert Mueller has a whole cadre of text messages and e-mails that suggest that he did not tell the truth," Butler said.

Watch below.