Sen. Al Franken (D., Minn.) said Tuesday on MSNBC that American college student Otto Warmbier was murdered by the North Korean regime that held him for 17 months.

Warmbier, 22, died Monday after returning to the U.S. from North Korea, where he had been imprisoned for 17 months. Warmbier was medically evacuated from North Korea in a coma. It is unclear what the original source of Warmbier's state was, but many believe its cause was mistreatment by the infamously brutal North Korean government.

MSNBC host Katy Tur asked Franken if he believed Warmbier had been murdered.

"I think this is the equivalent to murder, yeah," Franken said.

"They had them in his custody, and we hadn't seen him until he comes back in this coma. Yeah, that's the equivalent of murder to me. If I were the parents I would consider that, and I consider it that," he said.

At least one of Franken's Senate colleagues, Sen. John McCain (R., Ariz.), has also said that Warmbier was "murdered" by the North Koreans.