Julia MacIsaac was a compassionate and kind-hearted woman who worked at the University Health Network (UHN) as a medical lab technologist
She dated David Slinger for approximately 10 years. The two broke up in 2017.
Following the breakup, MacIsaac purchased a three-bedroom townhouse on Scarborough Golf Club Road where she allowed 45-year-old David Slinger to stay in a separate bedroom down the hall from her own.
MacIsaac had an independent locking mechanism on her second-floor bedroom which she had used to lock her bedroom from the inside.
In a downtown courtroom Friday, that ex-boyfriend pleaded guilty to second-degree murder, admitting he brutally killed MacIsaac in her own bedroom two years ago.
The agreed statement of facts are so disturbing, many of MacIsaac’s relatives left the courtroom before the facts were read into the record.
On March 14, 2024 at 4:08 am, Slinger called 911 and stated that he was in a psychosis, and that he had killed his roommate Julia through strangulation and then by hitting her over the head repeatedly with a baseball bat.
He told the 911 operator that she kept the bat in her bedroom.
When firefighters arrived, they found Slinger outside MacIsaac’s townhouse on Scarborough Golf Club Road near Kingston Road.
He told the fire crew that she was dead upstairs.
First responders then entered the home and found MacIsaac face-down on the floor in a pool of blood between the wall and the mattress of her bedroom.
She had significant trauma to her head and face, a severely broken right arm, and no vital signs.
A baseball bat covered in blood was found right next to her body.
Her independent locking mechanism was located on the bedroom floor.
A pathologist determined the 42-year-old’s cause of death was blunt force head trauma.
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There were also features supportive of neck compression, though their contribution to MacIsaac’s death could not be determined.
There were also injuries on her right arm which were consistent with defensive-type injuries, with the characteristics of these injuries suggestive of a rounded object such as a baseball bat.
Just a week before the murder, on March 7, 2024, around midnight, Slinger called an ambulance for himself. At the time, he was expressing suicidal thoughts and in an agitated state.
As a result, Slinger was apprehended pursuant to section 17 of the Mental Health Act and was transported by paramedics to Scarborough Centenary Hospital. He was later discharged on March 11, 2024, and returned to MacIsaac’s home.
The same day, at approximately 9:57 p.m., Ms. MacIsaac and Slinger’s sister had a conversation over text message about Slinger staying there after his discharge from hospital.
MacIsaac expressed that it wasn’t going well, but she was afraid to tell Slinger that she needs a break from having him stay there because he had nowhere to go and she didn’t know what he would do.
She also expressed to her partner that she was concerned about Slinger’s behaviour and felt uneasy about him staying there.
On March 13, 2024, at approximately 11:16 p.m., Slinger and MacIsaac had a conversation about household chores on the main floor of the residence.
Sometime after this conversation, Ms. MacIsaac went to her bedroom on the second floor of the residence.
On March 14, 2024, at approximately 2:30 a.m., Slinger was captured on video going up the stairs to the second floor of the residence in an agitated state.
He began banging on the door of Ms. MacIsaac’s bedroom and eventually forced his way inside.
The video camera in the stairwell captured the deadly attack.
Prior to calling 911, the facts state Slinger made a phone call to his sister Donna Slinger at approximately 3:50 a.m.
At approximately 4:01 a.m., he changed his clothing and then knocked over the camera in the second-floor stairwell, obstructing its view.
Ten minutes later, Slinger called 911.
MacIsaac was remembered as a” gentle and deeply empathetic” woman who loved animals, especially chinchillas whom she rescued. She was also dedicated to her work as a microbiologist.
“She should have been safe in her own home. Instead, she was violently murdered in it,” said Jennifer MacIsaac, Julia’s older sister. “It is unbearable to know that her life ended in fear.”
Jennifer told the court her sense of security has also been taken away and called her sister kind, passionate and loyal. “She saw the good in others, even when there was none,” said Jennifer.
Matthew MacIsaac told court he feels betrayed by Slinger. “Julia helped him for years, including by letting him live in her condo, and by helping him find a lawyer eight days before he killed her,” said Matthew.
He also said that Slinger delayed taking responsibility for his actions and made the family sit through a preliminary hearing.
Assistant Crown attorneys Ben Snow and Samantha Alston told Superior Court Justice Maureen Forestell that Crown and defence had agreed a life sentence with a parole ineligibility period of 12 years was appropriate.
“What is particularly tragic is that these same virtues of compassion and kindness is what made her vulnerable to this horrendous action of violence by David Slinger,” said Snow.
“At the time this occurred, she allowed Mr. Slinger to stay in her home as a lifeline for stability to prevent him from going to the streets, with his deteriorating mental health issues,” Snow added. “She put a lock on the door to prevent him from breaking through. The violation is aggravating.”
Defence lawyer Anthony De Marco said Slinger did not have a not criminally responsible (NCR) defence, though he said there was some information from psychiatrists before and after the murder that he was experiencing mania.
De Marco said Slinger had been diagnosed with bipolar disorder.
Forestell then sentenced Slinger to life in prison with a parole ineligibility period of 12 years, agreeing with the joint submission.
“If not for the mental health issues of Mr. Slinger, there’s no question the parole ineligibility period would be higher,” the judge concluded.


