Robert Reitmeier, who is 26, was found guilty last month of second-degree murder in the October 2010 death of Mark Mariani.
Mariani was walking down an alley to his parked car when he was savagely kicked and stomped.
The 47-year-old was frail with Crohn's disease and unable to defend himself.
Tyler Sturrup pleaded guilty to second-degree murder in March to the same crime and is to spend at least 10 years in jail before he is eligible for parole.
Reitmeier also faces a 10-year weapons prohibition should he be released from prison.
He showed no emotion Tuesday when he heard the sentence — which was essentially middle ground between the Crown's argument that his parole eligibility be at least 15 years and a defence suggestion that it be no more than 10.
Prosecutor Adam May explained outside court why the Crown was seeking a harsh sentence.
"Aggravating factors like the savage nature of the beating, the vulnerable aspect of the victim, the fact that the accused was on probation at the time of this offence were all factored into our reason for asking for 15 years," May said.
He added that it appears that Mariani was simply in the wrong place at the wrong time.
"Unfortunately we don't have an ascertainable motive as to why this happened and we may never know."
Mariani's relatives were in court Tuesday, just as they were last month when they gave victim impact statements at Reitmeier's sentencing hearing.
One family member read: "I will never forgive you for what you've done. I won't lose sleep over you, because you're nothing.''
Reitmeier was offered a chance to address the court at that time, but said nothing.
Sturrup, who helped found the Western European Bloodline supremacist group, admitted in court that he attacked Mariani for no reason.
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