David Moss Murders Seven Year Old Bella Rose Desrosiers

David Moss
David Moss

David Moss is a killer from Edmonton Alberta Canada who was convicted of the murder of seven year old Bella Rose Desrosiers

According to court documents Bella Rose Desrosiers mother was attempting to get David Moss mental health help and had brought him to a Edmonton hospital where he was accessed by doctors however the medical team did not believe he was a threat to himself or others under the mental health act

Later that day when Bella Rose Desrosiers was being put to be David Ross would appear at her door armed with a pair of scissors. He would push the seven year old mother to the side and brutally stabbed the little girl to death

David Ross would be arrested and charged with the murder of Bella Rose Desrosiers

At trial David Ross would attempt to blame his actions on psychosis that was triggered from a brain injury and that his sudden stoppage of using marijuana caused him to lose control and murder Bella Rose Desrosiers

The jury would find him guilty of second degree murder and he would be sentenced to life in prison with no chance of parole for fifteen years.

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David Moss Case

Cannabis use, not a brain injury, was the cause of the psychosis that gripped David Michael Moss’s mind when he brutally killed seven-year-old Bella Rose Desrosiers, a judge has ruled.

Court of King’s Bench Steven Mandziuk on Friday convicted Moss, 37, of second-degree murder for repeatedly slashing the girl’s throat as her mother tucked her into bed May 18, 2020.

Mandziuk rejected Moss’s claim he was not criminally responsible for Bella’s death due to a psychosis caused by a 2004 brain injury. Mandziuk found it more likely Moss’s marijuana use — which he abruptly halted while experiencing a spiritual “awakening” — was the cause of the psychosis.

“This was an unspeakable tragedy,” Mandziuk said. “Mr. Moss took a young child’s life in a shocking and agonizing way that has caused unimaginable damage to Bella’s family, friends and community.”

“The evidence establishes that it is more likely than not that Mr. Moss’s psychosis was not caused by the 2004 brain injury, but rather by cannabis-related causes — use, intoxication, withdrawal.”

Moss and Bella’s mother, Melissa Desrosiers, knew each other from high school and reconnected a year before the murder. A few months after, Desrosiers’s husband died by suicide and Moss, a tattoo artist, gave her a memorial tattoo

The day of the murder, Melissa picked Moss up at his home. She planned to take him to hospital, believing he was suicidal. An Edmonton police mental health team assessed Moss a few hours before but found no grounds to detain him under the Mental Health Act. Bella and her little sister were in the car and offered him a picture they had drawn.

Planning to have an aunt come by while she took Moss to hospital, Melissa tucked the girls into bed. Moss, meanwhile, showered and rested in the basement bedroom. Suddenly, he appeared in the doorway of the girls’ bedroom, naked except for his underwear and carrying an eight-inch pair of scissors.

Moss pushed Melissa aside and slashed Bella’s throat. He pulled her from the top bunk as her mother desperately fought to stop him. He then dragged her body down to the living room and continued the attack.

After he had finished, Moss sat on the couch and waited. Screaming, Melissa grabbed the scissors, threw them outside and tried in vain to treat Bella’s wounds.

Moss was arrested and told police he had cut his fingers during a “murder.” He later made a series of unsolicited comments, including “do you know why I did it? Cause I f—ing liked it.” He also called himself a pedophile, and said he’d had sex with his dog.

While in custody, Moss continued to make bizarre remarks and at one point repeatedly bashed his face into a concrete bench, knocking out teeth and leaving him in a pool of blood.

Crown and defence agreed Moss was psychotic, but disagreed on the cause. To be found not criminally responsible and be sentenced to a mental hospital rather than prison, Moss needed to prove it was more likely than not his psychosis was caused by a “disease of the mind” rather than induced by a substance.

Moss’s case focused on a 2004 traumatic brain injury, caused when Moss was hit on the head with a rock. Moss’s sister testified he became more withdrawn after the injury and suffered bouts of depression. He also suffered seizures, the last of which was in 2009.

Court heard extensively about Moss’s unusual behaviour in the lead-up to Bella’s murder. A year prior, he’d talked about killing his wife and their children. In the weeks before the killing, he claimed he was experiencing an “awakening, which was giving him “high levels of insight, gratitude, and freedom from fear,” Mandziuk said. Around the time of the killing, Moss was also caught up in a number of conspiracy theories around vaccines, 5G and aliens.

Moss was also a habitual marijuana user. At the start of the pandemic, which forced the closure of Moss and his wife’s tattoo shop, he increased his consumption, before suddenly stopping due to the “awakening.”

Marc Nesca, a psychologist who testified for the defence, diagnosed Moss with schizophrenia-like psychosis caused by the 2004 brain injury. He downplayed the role cannabis consumption played, saying the amount Moss used was relatively small.

The Crown, however, countered with two psychologists and a psychiatrist, who agreed cannabis use was at the root of Moss’s psychosis.

Mandziuk sided with the Crown experts. He noted their conclusion that it would be unusual for psychosis to suddenly emerge 16 years after the brain injury. He also had trouble believing Moss’s evidence, which was detailed in some places but sparse in others.

Mandziuk also declined a request from defence lawyer Rod Gregory to convict on the lesser offence of manslaughter.

“Being psychotic does not, in and of itself, negate intent,” Mandziuk said. “A person does not have to possess a clear and cogent understanding of reality to commit murder.”

Moss faces an automatic sentence of life in prison, with no chance of parole for 10 to 25 years. A date for sentencing has not been set.


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