The man had previously been sentenced to 18 years in prison, but the court of appeal considers that Obid Nazarov was so seriously injured that the attack is equivalent to a murder.
"We're very satisfied with the sentence and the trial in general. And my client is very satisfied," Marcus Lodin, the imam's attorney, tells Swedish Radio News.
On February 22, 2012, the imam, 54, was shot in the back of his head in a stairwell in Strömsund, in Jämtland. He was one of the toughest critics of the Uzbek dictatorship, and in 2006, was granted asylum in Sweden.
A 37-year-old man was arrested last year suspected of the crime. He confessed during the trial that he had travelled several times to Sweden to look for the imam at the request of a man from Moscow. But it is still unclear who hired the hitman.
The hitman's attorney, Jorge Concha, said that he hopes to take the case to the Supreme Court.