American actor Ryan Grantham has been sentenced to life in prison after pleading guilty to the murder of his mother Barbara Waite in 2020.

The 24-year-old, who played Jeffery Augustine in the teen drama Riverdale, was sentenced on Wednesday at the British Columbia Supreme Court in Vancouver.

After being charged with first-degree murder, he was convicted of second-degree murder.

Prosecutors said he also conspired to kill Canadian Prime Minister Justin Trudeau.

Grantham has admitted to shooting his mother in the back of the head while playing the piano at her Vancouver home.

'I killed my mother.’ In a video shoot with his camera after the murder, the Canadian actor was filmed saying his mother's body.

After drinking beer and smoking for a long time after the murder, he left his car with three guns and ammunition.

He set out for the city of Hope about 200 km east. After which he went to the Vancouver police station, where he told an officer: "I killed my mother."

Former child actor Grantham appeared in an episode of The CW network show Riverdale in 2019.

He shall not be eligible for parole for the first 14 years of the sentence of life imprisonment.