Ryan Grantham, a former actor on the Netflix series “Riverdale,” appeared in court in Vancouver, Canada, for sentencing after pleading guilty to second-degree murder.

Grantham fatally shot his mother, Barbara Waite, while she was playing piano in their Squamish, B.C., townhome on March 31, 2020.

Grantham told the court that he thought about shooting and killing his mother for days leading up to her death.

He stated, “My mother was a caring, compassionate, loving person. She did nothing to deserve what I did to her.”

Grantham, who is 24 years old, lit some candles and hung rosaries over the piano before leaving their home with a plan for more bloodshed.

He had been contemplating a killing spree and had a printed map of Rideau Cottage in Ottawa, with a plan to execute Prime Minister Justin Trudeau.

Grantham told police at the time of his arrest, “I was in a rush and he was the only person I could think of, the most important person in Canada.”

“Like, I could do something to make an impact.”

During his sentencing hearing, a forensic psychologist hired by the defence stated that Grantham’s mental state at the time was “far from normal,” describing it as unstable, chaotic, ambivalent, and fragile.

His lawyer, Chris Johnson, QC, argued that Grantham’s depressive disorder, cannabis use, and isolation contributed to his actions.

The court heard that Grantham was procrastinating in his studies at Simon Fraser University and had not been acting in a while.

He had rationalized his actions because he did not want his mother to see what he perceived as his failings.

Grantham’s acting career appears to have begun in 2007 with roles in TV movies.

He had credits in “The Imaginarium of Doctor Parnassus,” “Diary of a Wimpy Kid,” “iZombie,” and “Supernatural.” His last acting role was on “Riverdale,” in which he played a teenage boy who accidentally killed Archie’s father, Fred.

The episode centred around the fatal hit-and-run is a tribute to actor Luke Perry, who had died of a stroke earlier in the year.

The court heard that Grantham was contemplating mass murders on the Lions Gate Bridge between Vancouver and North Vancouver and at his university campus in Burnaby.

He also considered suicide after fleeing his home before turning himself in to police in Vancouver.

Grantham told the court that he is now committed to trying to do the right thing.

He joined a men’s support group at his remand centre and is showing a willingness to ask for help.

His lawyer stated that his client is a much different person now than he was in March 2020.

Grantham pleaded guilty to second-degree murder, which carries a life sentence with parole ineligibility for 10 to 25 years.

The judge assigned to his case will deliver her decision at a later date.

Grantham’s family sat in the front row of the court and was overcome with emotion as he apologized.

He stated, “In the face of something so horrible, saying sorry almost seems pointless. But from every fibre of my being, I am sorry.”