A Saskatoon man who admitted he tried to kill another man with an iron dumbbell last year has been sentenced to 15 years in prison.

Derek Watkins was charged with attempted murder for the Jan. 3, 2016 assault on Richard Lisko.

Prosecutor Gary Parker had argued for a life sentence. He said the severe sentence reflected the seriousness and savagery of the assault.

Watkins admitted in his confession that he had set out to kill Lisko, and that he left the scene believing he had committed murder, Parker said.

"He admitted the crime. This was a planned and deliberate attempted murder," Parker said in an interview.

"In his confession, which went into evidence, he admitted his intention was to kill the individual, and he thought he had. There was a significant impact on the victim. The victim is forever altered; the victim can no longer live independently."

Both men had been patients at the Dubé Centre for Mental Health. Parker said that Watkins lured Lisko away from the facility and then tried to kill him.

"The accused was operating under the impression that he was striking out because he had a perception about the victim, which was probably in error. That perception was based on his own childhood," Parker said.

The judge ruled that Watkins was criminally responsible for his actions.