Three years, three babies.

They were all placed into garbage bags by their mother while still alive, and thrown away with the trash in a dumpster just steps from her home.

It would be the third baby — found alive by his father in 2010 — who would prompt a police investigation leading to the discovery that two others had died previously in similar situations.

On Wednesday, the Alberta Crown asked the Supreme Court of Canada to overturn Meredith Borowiec's infanticide convictions and order a new trial on the charges she originally faced of second-degree murder.

It is the first time Canada's highest court is examining the country's infanticide law.

The Alberta government argued the wording of the law is vague, outdated and leaves too much room for new mothers to kill their babies, no matter their moral culpability.

"The woolly words of the [Criminal Code] section do not lend themselves to easy interpretation," said prosecutor Julie Morgan.

To find someone guilty of infanticide rather than murder, the judge or jury has to find that the mother was suffering from a mental "disturbance" at the time of the crime.

That is the word prosecutor Julie Morgan argued needs to be defined so as to "prevent this defence from being applied across the board to all mothers who kill their newborn children while only mildly disturbed."

But Borowiec's lawyers told the panel of seven judges the case had no business being in the country's highest court. If changes are to be made, it should be done by Parliament, argued Andrea Serink. She said no error in law had been made by the trial judge.

The appeal, she said, should be dismissed.

In 2010, Borowiec was arrested after police and paramedics found her sitting on her front steps, watching as first responders investigated a baby found alive in the garbage bin outside a housing complex.

Ian Turnbull, Borowiec's longtime, live-in boyfriend, was on his way home from work when he heard a baby's cries and jumped into the garbage and rescued the hours-old newborn.

Only after Borowiec's arrest would Turnbull learn he was the child's father.

Ian Turnbull, in the green sweatshirt, speaks with a CBC reporter in the days after he discovers his own baby in the dumpster. (CBC)

Borowiec was charged with attempted murder and released on bail, but police continued to investigate and, in a subsequent interrogation, she would confess to a Calgary homicide detective that there had been two other infants.

At the time of her second arrest, Borowiec was pregnant again and gave birth in custody.

She was charged with two counts of second-degree murder, but the Calgary judge who heard her case found Borowiec guilty of the much lesser offence of infanticide in 2013.

'Mental disturbance'

Two experts who testified at trial had conflicting opinions: psychiatrist Dr. Jeanette Smith testified for the defence, while the Crown used court-appointed psychiatrist Dr. Kenneth Hashman.

Hashman gave evidence that Borowiec's behaviour and detailed recollections of the crimes were inconsistent with someone who was suffering from a disturbed mind.

Smith told the judge Borowiec was panicked, anxious, and that those symptoms triggered de-personalization, resulting in the "disturbance."

In the end, Justice Peter McIntyre accepted Borowiec was not suffering from a "mental disorder" but did find symptoms showing a mental "disturbance."

A towel is found next to the dumpster where a newborn baby was discovered, alive, by his father. (CBC)

Infanticide carries a five-year maximum sentence. Borowiec was ordered to spend 18 months in custody, which was a far cry from the Crown's proposal of an 11-12 year prison sentence.

In a majority decision, the Alberta Court of Appeal rejected the Crown's application for a new trial on two counts of second-degree murder, finding that a change to the infanticide law was a matter for Parliament rather than the courts.

One of the three judges dissented, suggesting a review of the Criminal Code section and noted a lack of guidance relating to the definition of "disturbed."

History of infanticide

Almost 60 years ago, Parliament enacted infanticide legislation modelled on British laws that were originally designed to protect women who faced "dire social and economic circumstances."

Back in 1922, when England's Infanticide Act was introduced, women who killed their babies were often servants, and it wasn't uncommon for the fathers to be the women's employers.

Police investigate the scene in the hours after a newborn baby was discovered in a dumpster. Meredith Borowiec sat on her front steps watching until she was arrested and charged with attempted murder. (CBC)

"Unwed mothers faced oppressive social and economic situations including the stigma of illegitimacy, poverty, loss of employment and social isolation. Juries were sympathetic and were reluctant to convict these women of murder where the punishment was death," reads part of the argument filed with the Supreme Court by the Alberta government.

Canada's laws were enacted by Parliament with "little legal policy analysis and no debate on the validity of the underlying medical assumptions about the effects of childbirth on women."

The trial judge did not commit any error. The Crown has no right to appeal to this court on either issue. - Lawyer Andrea Serink

The Alberta Crown asked the panel of judges to redefine infanticide in the Criminal Code, arguing the defence is "vague, outdated and rife with problems."

The government says it is trying to "prevent this defence from being applied across the board to all mothers who kill their newborn children while only mildly disturbed."

In her interview with police, Borowiec acknowledged she knew she was pregnant but admitted she "did not want to deal with it."

A Calgary judge released a video confession in the trial of a mother accused of throwing two of her newborn babies in dumpsters. 5:23

The Crown proposed the wording read: "A woman has a disturbed mind if her psychological health is substantially compromised from the effects of giving birth and caring for a newborn."

Instead of arguing the law — that the trial judge erred in his application of it — the Crown argued the facts of the case, said Serink in explaining why the Supreme Court should dismiss the application.

"The trial judge did not commit any error," said Serink. "The Crown has no right to appeal to this court on either issue."

Also involved in Wednesday's hearing were three interveners, interested parties who applied to make submissions on the application.

A lawyer for the Ontario Attorney General sided with the Alberta government in proposing the court define "disturbed."

And joining the respondent in asking the appeal be dismissed were the Ontario Criminal Lawyers' Association and the Women's Legal and Educational Action Fund.

"There's no evidence or proof this [current definition] is difficult for jurors to grasp," said Jonathan Dawe with the Lawyers' Association.

Borowiec has served her sentence and is currently on probation.

The court reserved its decision.