A Calgary teen who weighed 37 pounds had been lying dead in his home for up to 36 hours before 911 was called, according to evidence from the first officer on scene who testified at the murder trial of his parents.

Rodica and Emil Radita are charged with first-degree murder in their 15-year-old son Alex's death in May 2013.

Const. Larry Pugliese said that Emil Radita told first responders he found his son unresponsive around 8 p.m., but the officer was later told by medical investigator Shauna Mitchell that there was "no way" the teen was alive at that time.

"Her assessment was 12 to 36 hours he'd been deceased," said Pugliese.

When Pugliese and Mitchell asked the Raditas why there was such a "huge delay" in calling for medical help, the Raditas told him it had been their son's choice.

"Emil had said that he told [Alex] that he needed to go to the hospital but he refused and said that he didn't like to go to hospitals because he had a bad experience when he was three years old," said Pugliese.

Mitchell and Pugliese then took the parents into a bedroom to talk about the circumstances surrounding their son's death.

Rodica told them Alex had no medical issues.

"That's when I spoke up," said Pugliese, who had been told about Alex's diabetes diagnosis just after 10 p.m. when he arrived at the family's home.

Rodica responded that her son had been diagnosed at age three, but said she did not believe he was diabetic.

Alex was diagnosed with Type 1 diabetes when his family lived in Surrey, B.C., and was hospitalized numerous times.

Earlier in the Court of Queen's Bench judge-alone trial, Justice Karen Horner heard evidence that the family had a history of refusing to treat Alex's diabetes. He was seized from them for a year by B.C. social services after he nearly died.

The judge has yet to rule on the admissibility of the B.C. evidence.

The parents told police and paramedics that Alex had the flu for three days leading up to his death and had been dealing with diarrhea for about a month.

Alex Radita 'beyond hope'

When Pugliese first arrived at the Radita home, one of the paramedics told him that Alex was "beyond hope."

"When I looked at the boy, my first instinct: he's dead," Pugliese said. "It was like a skeleton."

The boy's body was on a bed in the middle of a bedroom, and paramedics were not working on him.

One of the first paramedics on scene testified last week that Alex was cold to the touch, not breathing, and had no pulse when she arrived.

Pugliese said he gathered the 20 people he'd first encountered in the family's driveway, and had Rodica and her other seven children in the kitchen.

All of the children lived at home, including five adults, who ranged in age from 18 to 23 years old. None were ever charged.