Demonstrators hold placards featuring an image of former US intelligence contractor Edward Snowden as they take part in a protest against the US National Security Agency (NSA) collecting German emails, online chats and phone calls and sharing some of it with the country's intelligence services in Berlin on July 27, 2013. AFP PHOTO / JOHN MACDOUGALL (Photo credit should read JOHN MACDOUGALL/AFP/Getty Images)

WASHINGTON -- National Security Agency whistle-blower Edward Snowden has been slammed by some as a “coward” for refusing to turn himself in to U.S. authorities and face espionage charges for shedding light on secret surveillance programs. But one of the lawyers involved in the Vietnam-era Pentagon Papers case has said that Snowden was justified in seeking sanctuary in Russia.

In a Friday interview on "The Agenda" on SiriusXM Progress, Daniel Sheehan said that Snowden wouldn’t receive a fair trial if he returned to the U.S.

“No American citizen in their right mind would trust the honesty and the objectivity of the American judicial system at this time in history,” Sheehan said. “They are not trustworthy. The majority of the United States Supreme Court is not trustworthy. They have given themselves over to this same national security state mentality.”

Russia has granted Snowden temporary asylum for one year. Earlier this month, Sen. Chuck Schumer (D-N.Y.) called Russia's actions a betrayal. The senator went on to label Snowden a "coward."

"Others who have practiced civil disobedience in the past have stood up and faced the charges because they strongly believed in what they were doing," Schumer said. "Mr. Snowden is a coward who has chosen to run."

Sen. John McCain (R-Ariz.), during a Fox News Sunday appearance, speculated that younger Americans might view Snowden as a modern-day hero -- "some kind of Jason Bourne."

"There's kind of a generation change here. Young Americans don't trust this government," McCain said.

On "The Agenda," Sheehan offered to represent Snowden if the Obama administration made certain assurances, including agreeing not to prosecute Snowden under the National Defense Authorization Act.

“I'd be perfectly happy to work with others to persuade Edward Snowden to come home," Sheehan said. "I think we would win that trial just like we won the Pentagon Papers case."