A Toronto woman has been found not guilty of manslaughter in the death of a toddler left in her care in 2013, an Ontario Superior Court Justice has ruled.

Justice Gary Trotter acquitted Maria Sosa in a Jan. 8 decision, saying that while he did not feel comfortable calling Allison Tucker's death accidental, there was too much uncertainty surrounding the circumstances not to raise reasonable doubt.

"Allison Tucker's death is an unspeakable tragedy [but] we will probably never know how this little girl died," Trotter wrote in his decision. "There are inconsistencies and peculiarities in [Sosa's] accounts. However, some consistent themes emerge."

The agreed statement of facts show that the toddler, just months shy of her third birthday, got dropped off at her babysitter's home around 7 a.m. by her mother. Sosa and the girl's mother, Amanda Tucker, had worked together, before Sosa decided to become a stay-at-home parent after the birth of her second son, then 2.

Arrived in perfect health

Allison seemed in perfect health that morning, except for a few abrasions around her mouth, "innocently acquired" after a recent family trip to Marineland, Trotter wrote.

Her babysitter testified that she had given Allison a bath after the toddler wet herself before a planned trip to the park that morning. She said she left the girl alone "for about a minute" in approximately eight to 10 centimetres of water so that she could retrieve some clean clothes.

When Sosa returned, she testified that Allison was lying on her back and vomiting in the water.

But when the first paramedics, police and firefighters arrived at the apartment building within nine minutes of Sosa's call to 911, the toddler was cold and unresponsive. She would be pronounced dead at the hospital.

The case circled around several core issues, particularly how long Allison was left in the bath, the depth of the bathwater — and whether the girl had been assaulted as the Crown prosecutor claimed.

Autopsy inconclusive

An autopsy by forensic pathologist Dr. Michael Pollanen found bruising to Allison's head and neck, but he was not able to conclude exactly how she sustained those nor say conclusively how she died, although it could have been from drowning or, less likely, he said, from strangulation.

"Although the circumstances are very troubling and cause serious suspicion, I am unable to conclude beyond a reasonable doubt that Ms. Sosa assaulted Allison," the judge wrote.

"This was an extremely difficult case for everyone involved and an absolute tragedy."  - Maria Sosa's lawyer, Breese Davies

Trotter found some inconsistency in the length of time between Sosa's finding Allison in the tub and her decision to call 911, as well as some inconsistencies in exactly how long the toddler went unsupervised. 

But he ruled that while he would not call the death accidental, there was not enough evidence to conclude with certainty that Sosa was responsible.

Sosa did not want to speak to the media about the case, her lawyer Breese Davies told CBC News.

"Justice Trotter came to the right result and we are very pleased with the outcome," Davies said in an email Sunday. "This was an extremely difficult case for everyone involved and an absolute tragedy." 

The Tucker family could not be reached for comment by CBC News on Sunday.