Some of the them had tears in their eyes as the verdict that could put Mitchell, 57, behind bars for the rest of his life was read, The Salt Lake Tribune reported.
"I was shaking and my eyes were welling up," a man, identified only as Juror No. 10, told reporters after Friday's verdict.
Mitchell and his wife, Wanda Barzee, abducted Smart, then 14, in 2002 and held her captive for nine months.
All seven men and five women met with the news media at the conclusion of the trial in U.S. District Court. They asked to be identified only by number, the Tribune said.
Jurors were impressed by Smart's three days of testimony and the evidence of Dr. Michael Welner, a forensic psychiatrist who testified for the prosecution.
Some jurors said they were impressed by defense lawyer Robert Steele's closing argument because he did not paint Mitchell as a saint.
"He characterized him so honestly, that he was not a good guy, not someone you want as a neighbor," a woman who works in healthcare said. "He treated us with respect, too."