Alex Radita was "emaciated to the fact that he looked mummified" according to the testimony of a paramedic who was called to the Radita home in May, 2013.

The first-degree murder trial for Alex's parents, Rodica, 53, and Emil Radita, 59, began Tuesday morning.

Alex Radita, 15, weighed less than 37 pounds at the time of his death. His physical condition was so disturbing, many of the emergency responders who found the emaciated child inside the family's home had to seek psychological services.

"It is hard to imagine what Alexandru experienced in the last days, weeks and months of his life," prosecutor Susan Pepper said in her opening statement.

"It must have been painful. It must have been profoundly lonely."

The Raditas once had their son seized by B.C. social services after he nearly died from untreated diabetes — the same allegations they now face in relation to his death, according to Pepper.

'Nothing left'

When EMS was called to the home in May 2013, they encountered about 20 people who were inside, kneeling, chanting and praying, according to paramedic Debroah Baumback's testimony Monday afternoon.

Once inside, Baumback says she and her team made their way upstairs to Alex's room where they saw him lying on a bed in the middle of the room.

"I actually remember walking in the room thinking 'what the hell is that,'" said Baumback. "[Alex was] emaciated to the fact that he looked mummified."

The boy had sores on his face that were black and necrotic and was so "extraordinarily skinny" that she said there was "nothing left."

Alex was not breathing, he was cold to the touch and had no pulse.

Emil Radita told the paramedics that his son had been diagnosed with diabetes a month earlier and had suffered from chronic diarrhea for a month, said Baumback.

She also testified that Alex's father said he called friends from his church before he called 9-1-1.

'It looked like he was dead'

"At some point the accused knew their plan was killing their son or they knew he was likely to die and they accepted this consequence," said Pepper. "They knew this and yet they continued their plan."

Items seized from the Radita's home included baby food from Alex's room, unused insulin, and an unsigned note, written by one of Alex's siblings and introduced as evidence by Cst. Jeanne Dewitt.

The sibling describes walking by Alex's room before he died and seeing his mother lifting the sick boy.

"I saw his face, it was so scary," read the note. "It looked like he was dead."

The sibling then writes about getting a bible and praying with a sister.

"[We] started to pray, the Holy Spirit said he was in paradise."

Complications from diabetes

Police said at the time that Alex, who had Type-1 diabetes, died from a bacterial infection that arose from complications stemming from neglect and starvation.

The Raditas had several adult children who also lived in the home, but none of them were ever charged.

The family had moved from B.C. several years before Alex's death, where court documents show his parents had a history of refusing to treat the boy's illness.

The trouble began in 2000, when Alex was first diagnosed with diabetes at age three.

Child seized by B.C. social services

The child was hospitalized several times before B.C. social services officials seized him for a year. He was returned to his parents in 2005.

A court document obtained by CBC News and written by a B.C. judge outlined how the parents did not trust their son's diabetes diagnosis and mismanaged the disease, detailing long periods of time when the boy was not seen by a doctor.

In his written decision to return Alex to his parents about a year after he was removed, the judge wrote that he believed the boy would be safe at home.

His parents were required to take Alex to a doctor as part of the conditions of his return, but at some point they stopped and moved to Alberta.

Once in Calgary, Alex was home-schooled, and was never taken to see a doctor. He had no contact with the world outside his home so nobody noticed his deteriorating condition, according to police.

"His parents set themselves up to be the sole keepers of his life and then they withheld that life by denying him the very things that he needed to live; insulin, nutrition and medical care," said Pepper.

Trial by judge

The case has raised questions about how Alberta and B.C. share social services information.

The Crown will call more than 30 witnesses over the course of the five-week Court of Queen's Bench trial.

Originally set to be tried by judge and jury, the couple has chosen to be tried by a judge alone. Justice Karen Horner is overseeing the case.

Rodica Radita is represented by lawyer Andrea Serink, while her husband, Emil, has retained Jim Lutz.