He said his brother fixed cars for a living.
"He spent his time putting bread on the table," he said.
Chechnya has been plagued by an Islamic insurgency that has carried out deadly bombings.
Tsarni said vehemently that Chechnya had nothing to do with the attack. "I've been following from Day One, but would never imagine that somehow the children of my brother would be associated with that. So it is atrocity."
Ruslan Tsarni said he is a native Chechen, but "I love this country."
Earlier, in a telephone interview with WBZ TV of Boston, the uncle said his nephews had been in the United States since about 2000 or 2001.
When told that the older brother, Tamerlan, had died overnight, he said, "Good. He got what he deserved."
He called Tamerlan a "loser."
But he said the younger brother was considered a "success" — that he graduated from high school and either had started to go to college or was admitted to college.
He said he saw the FBI videos on TV yesterday, but did not recognize his nephews at the time.
"I'm wordless. I'm shocked," he said.
WBZ also reported that the father of the two suspects said Tamerlan was an "accomplished medical student ... an angel."
Another uncle, Alvi Tsarni, also of Maryland, was in shock.
"They killed my nephew. It's not possible he did this thing," he told WBZ from his home.
He said he had not talked with his nephews' side of the family for about two years because there had been "some problems with the family."
He said that yesterday he got a call from one of his nephews saying "Forgive me."