A Canadian court has halved the sentence of a woman who killed her husband, revisiting a controversial case that revealed the legal system’s “outdated thinking” of the realities of domestic abuse.

In a 2-1 ruling released on Wednesday, Alberta’s court of appeal determined that Helen Naslund’s 18-year sentence should be reduced to nine years.

“It is beyond time for this court to explicitly recognize that cases of battered women killing abusive partners involve unique circumstances that must be considered by the sentencing judge, particularly where battered woman syndrome is involved,” Justice Sheila Greckol wrote for the majority.

According to an agreed statement of facts, in 2011 Helen Naslund, a grandmother of eight, shot her husband, Miles Naslund, in the back of the head while he slept. The killing came after Miles Naslund had physically and emotionally abused her for nearly three decades, prompting Helen Naslund to attempt suicide on multiple occasions. After the killing, Helen Naslund and her sons hid Miles Naslund’s body in a pond on their property, buried his car and kept the crime a secret for six years.

While her son Neil received a three-year sentence, Helen Naslund agreed to a joint submission by the defence and crown prosecutors that would see her serve a sentence of 18 years for manslaughter, thereby avoiding a trial and the likelihood of a far harsher sentence if convicted.

The sentence made headlines back in 2020 as one of the longest handed down in the case of an abused woman killing her partner and prompted more than 25,000 people to sign a petition in her defence.

In the appeal court’s decision, Greckol faulted the sentencing judge, Sterling Sanderman, for his failure to account for the decades of abuse Naslund suffered.

“The sentencing judge suggested that Ms Naslund had ‘other options’ open to her, implicitly the option to walk out the door,” Greckol wrote. “For the sentencing judge to suggest that battered women have ‘other options’ is to invoke a stereotype that a battered woman stays in a situation of domestic violence by choice.”

Greckol also found the sentence of 18 years was excessive, pointing to a number of previous cases in Canada where sentences ranging from a suspended sentence to eight years.

“Counsel … failed to fully explain to the sentencing judge how they arrived at a sentence markedly harsher than those imposed in similar cases,” she wrote.

Writing in the dissent, however, Justice Thomas Wakeling disagreed there was evidence of battered woman syndrome and argued that if Naslund’s case had gone to trial, she would probably have received life in prison with no chance of parole for nearly two decades.

“I am satisfied that the notional reasonable observer would conclude that Ms Naslund has no good reason to complain about this bargain,” he wrote of the deal reached between prosectors and the defence, adding that she never claimed to have received poor legal counsel. “It has probably saved her many years of prison time.”

In a statement issued through her lawyer, Helen Naslund said she was “incredibly grateful” for the support she had received over the years.

“I hope that other women can benefit from the court’s recognition of the terrible situation in which battered women find themselves.”

Her son Neil told CBC News he was happy with the outcome.

“She will get to spend more time involved in her grandkids’ lives and have the chance to see her very senior father before he passes, and for that I’m very happy,” he wrote in a text message.

With her reduced sentence, Naslund may be able to apply for parole by the end of 2022.

Alberta’s crown prosecution has 60 days to decide if it will appeal Wednesday’s decision to Canada’s supreme court.