A 39-year-old woman has been charged with manslaughter in the death of her four-year-old son after investigators spent more than a year probing the case, police in southern Ontario said Friday.
Hamilton police said they arrested the woman in Newfoundland, where she had given birth to another child in the months since her son died in September 2017 after a long history of medical issues.
Police said they originally did not have grounds to suspect foul play when they were called to the woman's home for reports that her son was unresponsive.
"(The boy) was born with a number of medical issues resulting in several major operations and many months of hospitalization," the force said in a statement. "In September 2017, it appeared that (he) had overcome the worst of his challenges and he had recently started junior kindergarten."
Police said, however, that it's a matter of routine to investigate the death of a child under the age of five.
While initial autopsy results did not raise any red flags, police said the results of a toxicology screening released three months later showed a lethal dose of unspecified drugs in the child's system. That led police to officially designate the boy's death as caused by "drug poisoning."
Although the death was immediately classified as a homicide, police said they chose not to disclose that fact at the time.
The force notified the boy's parents of the toxicology results in February 2018 and informed them that they were officially viewed as suspects in his death. His mother and father, who police said had previously co-operated with investigators, stopped doing so at that point.
Police said their lengthy investigation into the boy's death focused initially on identifying the source of the drug involved in the child's death.
They said they reviewed medical records belonging to both the boy and his parents and ultimately formed "reasonable grounds" to charge his mother. They did not provide details on those grounds.
Police said it was while conducting their investigation that they learned the mother was pregnant. The local Children's Aid Society was notified and alerted nearby hospitals to watch for the child's birth, but police said the mother travelled to Newfoundland to deliver the baby.
Child protection authorities notified the Department of Children, Seniors and Social Development in that province, police said, adding the new baby was taken into protective custody.
The boy's mother was still in Newfoundland when she was arrested on the manslaughter charge on Wednesday, police said.
She was flown back to Ontario and appeared in a Hamilton courtroom on Friday morning, where she was remanded into police custody.