The disturbing moment when a Canadian teen dressed in all black garb stabbed a senior woman to death as she raked leaves in her front yard was caught on camera.

Eleanor Doney, 83, was fatally stabbed in front of her Lynn Heights Drive home in Pickering, about 25 miles east of Toronto, Ontario, by a 14-year-old boy last May 25.

In the footage, the teenager, whose identity has not been disclosed as it is protected by law in Canada, was wearing a black mask, trench coat and gloves, according to the National Post.

His distinct look also included overly large dress shoes and a soft shell briefcase in his hand.

Once the boy walked past Doney, he put his briefcase down and spoke to her for about two minutes, per the outlet.

After that, he retrieved a knife from his briefcase and stabbed Doney in the left side of her neck.

As she fell backwards and tried to return to her home, the teen repeatedly swung at Doney before running away.

Doney was rushed to the Sunnybrook Health Sciences Centre hospital in Toronto after a passerby saw her lying on the ground in front of her home. 

The stranger attempted to resuscitate Doney to no avail.

Further attempts at the hospital were also unsuccessful and she was declared dead around 4pm.

The teen boy pleaded guilty to first degree murder in April, according to CBC.

Peter Moreira, the Durham Regional Police Chief, called Doney's death a 'senseless murder' that had devastated a family and shaken the city of Pickering.

'The brutality and gratuitous nature of this crime—captured on video—is shocking, and it underscores the dangerous influence that online platforms can have on young people,' Moreira wrote on X in April.

Durham Regional Police were the ones who obtained the footage that showed the moment Doney was murdered, according to the Toronto Sun. 

Doney's husband, Bruce Doney, told court that he and his wife had been together for 63 years. He said he had been forced to move into a long-term care home after her death.

'With my many health problems which are age-related I am disabled and my wife was my supporter, my main caregiver,' he said, per the National Post.

Immediately after Doney was murdered, local police directed residents to stay indoors while he was located.

He was identified by school administrators, and his knife was found discarded in a wooded area.

When law enforcement looked through his home, they found a missing knife from a Cuisinart kitchen set that appeared to match the one discovered in the woods.

Police said that the teen had watched 15 videos last May 20 and 21 about how to tell whether one is a psychopath or a sociopath.

He also searched 'how serial killers got away' twice the following day and watched a four-hour long video covering the 'most sadistic serial killers' ever.

Another video that he watched was about how to apply maximum pressure when stabbing someone.

On the day that he murdered Doney, the teen looked up the schedule for trains leaving Pickering.

He was on social media just four minutes before he stopped in front of Doney's house.

His browsing continued after returning home, where he watched Breaking Bad, Family Guy and Iron Man. This continued up until he was arrested by Canadian police.

He will be sentenced in July. 

The Daily Mail has reached out to Erin Dann, the teen's lawyer, for comment.