Cambridge woman found not criminally responsible in fatal stabbing of her daughter

A Cambridge woman charged with second-degree murder in connection to the fatal 2020 stabbing of her daughter has been found not criminally responsible.

Melissa Duff-Shore was found not criminally responsible for the death of 22-year-old Kayla Duff due to 'reason of mental disorder – automatism.'

Automatism is defined as a state of unconscious, involuntary behaviour.

Police were initially called to a townhouse complex in Cambridge on September 11, 2020.

Police and Animal Services at the scene of a homicide investigation in Cambridge. (Sept. 11, 2020)

A victim, later identified by her family as Kayla Duff, died of multiple stab wounds.

At the time, Kayla’s sister Samantha Duff-Foley told CTV News via a statement, "Kayla was among many things the most genuine, caring and loving person I have ever known."

Multiple 911 calls

An agreed statement of facts obtained by CTV News states Duff-Shore contacted 911 at least three times in the weeks leading up to Kayla Duff’s death.

The document states Duff-Shore contacted the emergency line on August 19th and told the call taker, “I’m at risk to the person that lives in the home” and asked to be removed from the home she shared with her daughter. She also stated she was “trying not to harm her,” and “I need to make sure that she’s home safe.”

When the call taker asked Duff-Shore why she felt that way, Duff-Shore said, “I haven’t dealt with things accordingly.”

Duff-Shore told the 911 operator she was suffering from mental health issues.

Duff-Shore called 911 twice more on August 20. She was asked if she was feeling violent or dangerous to anyone else or to herself. She said she was “calling to prevent that.”

The call transcript also states Duff-Shore told the call taker she had been talked out of being removed from the premises the night before.

She told the call taker she needed “an intervention at the house.”

Later in the call, she said, “I realize I’m terrifying,” and “I don’t want to cause further harm.”

The agreed statement of facts also shows Duff-Shore told her daughter not to invite any guests to the home on September 10 and then took three medications: Seroquel, Hydromorphone, and Zopiclone.

Duff-Shore said she remembers waking up on September 11 after passing out the day before. When she woke up, she had blood on her arms and hands and there was a dried pool of blood in her lap. She said she tended to a wound on her arm and then noticed the body of her daughter at the foot of the staircase.

Duff-Shore called 911 to report the death.

A post-mortem examination of Kayla Duff concluded she had suffered at least 70 distinctive sharp force injuries. Two of those injuries were to her neck and were ultimately ruled as her cause of death.

Duff-Shore told police she had no memory of having hurt her daughter and could not remember what caused the injuries to her arms and hands.

While searching the home, police found three knives with Kayla Duff’s blood on them. One of the knives was broken at the handle.

The agreed statement of facts show when Duff-Shore was asked about her daughter, she told investigators, “She’s dead, no reason other than me. There’s no reason she should be dead.”

With reporting from Natalie van Rooy and Chase Banger