This morning on Fox News Sunday, Senate Intelligence Committee Chairman Dianne Feinstein (D-Calif.) said she “very strongly” believes it would be “unconstitutional” to try Tsarnaev in a military commission.

“I very much regret the fact that there are those that want to precipitate a debate over whether he’s an enemy combatant or whether he is a terrorist, a murderer, et cetera,” Feinstein said. “…There is time to do the investigation, to make a clear assessment, and to move from there. So I really regret all of this discussion, which is creating a conflict that need not be there. The administration is ready for this.”

Countering Feinstein, King said on the program it’s necessary to treat Tsarnaev as an enemy combatant for the purpose of interrogation.

“The reason for it is, there’s so many questions unanswered. There are so many potential links to terrorism here. Also, the battlefield was now in the United States. So, I believe he is an enemy combatant,” King said.

The former House Homeland Security Committee chairman clarified that as an enemy combatant he can still be tried in civilian court, though statements taken from him in the interrogation phase wouldn’t be able to be used there.

“Right now, he’s really the only link we have as far as any Chechen involvement in al-Qaeda movement, in the overall Islamist movement, and we don’t know, are there other conspirators out there? Are there explosives out there?” he continued. “Where do they get the radicalization? Are there mosques, imams we should be looking at? Who did his brother meet when he was in Russia, in Chechnya?”

King said people need to get off the argument that the criminal courts system is adequate because it’s successfully prosecuted terrorists before. “I don’t worry about conviction. I don’t worry about a conviction. He’s going to be convicted,” he stressed. “I want the intelligence so we can save American lives. And that can only be done I believe, effectively, if he’s treated as an enemy combatant” without access to a lawyer.

“When the public safety exception expires and it will here soon, this man in my view should be designated as a potential enemy combatant and we should be allowed to question him for intelligence gathering purposes to find out about future attacks and terrorist organizations that may exist that he has knowledge of. And that evidence cannot be used against him in trial. That evidence is used to protect us as a nation,” Graham said on CNN’s State of the Union.

Sen. Chuck Schumer (D-N.Y.) said “the good news is we don’t need enemy combatant to get all the information we need out of him.”

“I don’t think we have to cross the line and say he should be an enemy combatant which could be challenged in court,” Schumer said. “One circuit is ruled one way, one circuit has ruled another way.”

Feinstein said they’ve discovered “there was very likely a call from Russia before he went back to Dagestan and Chechnya,” and Tamerlan Tsarnaev was back there for six months.

“I think there is likely going to be an assessment that this was somebody who did want to participate in a jihadist event,” she said.