An Alberta prosecutor says a couple that failed to seek medical attention for their son who later died of bacterial meningitis were aware that he was suffering from a form of the deadly infection.

David Stephan and his wife, Collet, are charged with failing to provide the necessaries of life to 19-month-old Ezekiel in 2012.

The Stephans have testified that they originally thought Ezekiel had croup, an upper airway infection, and that they treated him with natural remedies, including a tincture of garlic, onion and horseradish added to a smoothie.

They said he appeared to be recovering at times and they saw no reason to take him to hospital despite his having a fever and lacking energy.

A family friend, who is a nurse and midwife, testified that she advised Collet to get a medical opinion the day before the boy stopped breathing. The friend feared "something more internal like meningitis."

"It's the Stephans failure to respond to what I would say to increasingly alarming information or feedback from their child during that period of time," said Crown prosecutor Britta Kristensen in her closing argument Thursday.

"Both parents knew the child had meningitis."

Kristensen said by doing so the Stephans endangered Ezekiel's life.

"Knowing that he had meningitis — there were forms of it that are fatal and fast acting — it was incumbent on them to see a doctor and a doctor's supervision," she said.

"There was no decision to take him to a physician notwithstanding his declining health over the next two days."

Stephan representing himself

Stephan, who is representing himself, said in his final argument that evidence suggests a failure by medical professionals to properly intubate his son was the real reason Ezekiel died.

Testimony indicated the boy was without oxygen for nearly nine minutes because the ambulance that took him to hospital wasn't properly stocked with breathing equipment to fit a child and Ezekiel was without oxygen for close to 9 minutes.

"There was a request made for equipment for approximately one year. Those requests were never honoured. The ambulances were never equipped," said Stephan.

"Within a week of Ezekiel's passing ... magically the ambulances are restocked. I think these are grounds for misrepresentation and a coverup. I'm no expert in law but I think that would constitute a case of criminal negligence resulting in death."

Stephan told the judge he feels there were elements of prejudice against him and his wife because they were sovereign citizens — people who believe in common law and don't feel they are responsible to any government.

"It is my position that the Crown has not proven its case," said Stephan. "I respectfully ask that it be a not guilty verdict."

It is the second trial for the Stephans. The Supreme Court of Canada overturned their original conviction.

'Bad things happen to good parents'

Jason Demers, arguing on behalf of Collet Stephan, said the parents thought they were doing the right thing in caring for Ezekiel.

"They are not stupid and I would submit to you that if they believed there was a problem they would have taken Ezekiel to a hospital," Demers told Justice Terry Clackson, who is hearing the case without a jury.

"These parents are still looking for answers. They still don't quite understand how it happened. It's been a quest for truth for them for seven years."

Not even a prudent parent makes the right decision all of the time, Demers said.

"Parenting, like the practice of medicine, is not like looking in a crystal ball," he said. "Bad things happen to good children without rhyme or reason and bad things happen to good parents."

Justice Clackson said he would render his verdict on Sept. 19.