He stated on Monday, Mar. 2 at the Council on Foreign Relations in New York, Censor.NET reports citing The Wall Street Journal.
Clapper called the possibility that Russian political leaders were involved in Mr. Nemtsov's death an "obvious theory," but noted that people close to Russian president Vladimir Putin are alleging the U.S. government was behind the killing in order to spark division within Russia.
"We don't have any unique insight into who did this," he told the Council on Foreign Relations in New York. "I would venture the history has been we never do find out."
But Clapper didn't leave it at that.
"I'm sure that Putin himself personally is going to investigate," he said smiling wryly.
The well-known Russian opposition politician Boris Nemtsov was shot dead in downtown Moscow on the night of Feb. 27. Nemtsov was shot several times in the back from a passing car. He died on the spot due to injuries.