President Donald Trump's former lawyer, Michael Cohen, has been sentenced to three years in prisonfor crimes that included making hush money payments to two adult film stars who claimed they had a relationship with his then-boss.

Homeland security expert Juliette Kayyem told Boston Public Radio Wednesday that the sentencing may provide some clues about where the Russia investigation is headed.

She pointed specifically to comments made by a lawyer from special prosecutor Robert Mueller's office, Jeannie Rhee, who said that Cohen had "sought to tell us the truth and that is of the utmost value to us" and had "provided consistent and credible information about core Russia-related issues under investigation."

"Mueller's attorney stated unequivocally, 'Michael Cohen has told us the truth,'" Kayyem said.

"That, to me, is fighting words — and it's not fighting words to the judge in terms of, 'Don't sentence him hard,' it is fighting words to everyone else watching," Kayyem said, "because there's no way Mueller's lawyer would say that unequivocally unless they had documentation, texts, phone calls, photographs, whatever it is validating the collusion side."

Kayyem interpreted Rhee's comments as a message to other people within Trump's circle who may have information about the crimes committed.

"Remember [prosecutors] are using the court case to say to people: 'This case is essentially over, do you want to help or do you want to end up in jail?'" she said.