The Crown is appealing the sentences imposed on Colton Steinhauer, who was convicted of first-degree murder in the killings of two Mac's convenience store clerks in 2015.

Last month, Steinhauer was sentenced to life in prison with no chance of parole for 25 years for murdering and robbing Karanpal Bhangu and Ricky Cenabre, who were shot to death while working overnight shifts at separate south-Edmonton Mac's stores in the early hours of Dec. 18, 2015.

The Crown had asked Court of Queen's Bench Associate Chief Justice Ken Nielsen to impose consecutive sentences, meaning Steinhauer would have served 50 years before being eligible to apply for parole.

But Nielsen said 50 years behind bars "would remove all hope" for Steinhauer. "He would have no chance of a life outside prison if he was given 50 years."

In addition to the concurrent 25-year sentences for murder, Nielsen sentenced Steinhauer to two eight-year sentences for robbery with a firearm. Those sentences were to be served concurrently to the life term. Steinhauer is imprisoned at Edmonton Institution.

"The sentence imposed is demonstrably unfit," the Crown says in its notice of appeal, filed Thursday.

The Crown further says Nielsen failed to properly assess the criteria for imposing consecutive sentences, that he "erred in the assessment of the aggravating and mitigating factors," and "failed to properly assess the principle of deterrence and denunciation" as sentencing factors.

Laylin Delorme, Steinhauer's co-accused in the murders and robberies, is serving a sentence identical to the one imposed on Steinhauer.

The Crown, which had also sought consecutive life terms for Delorme, filed an application in January of this year seeking leave to appeal his sentence.

"The sentence imposed is not proportionate to the gravity of the offence and degree of responsibility," the Crown application said.

Delorme is appealing his conviction, arguing that the jury's verdict in his case "was unreasonable or cannot be supported by the evidence."

A teenaged relative of Delorme has already completed a three-year sentence after pleading guilty to two counts of manslaughter.