A Vancouver man convicted of murdering his mother inside her own west side home has been sentenced to life in prison with no chance of parole for 12 years.

Brian Whitlock was sentenced Wednesday for the brutal slaying of his mother, Barbara, whose body was found in the city's Dunbar neighbourhood in November 2014.

After learning his fate, Whitlock asked the judge, "Has it really taken three years to get to this point?"

The discovery of his mother's death prompted an eight-hour standoff between Whitlock and police at her home. Officers eventually used a flash-bang and non-lethal ammunition to take the killer into custody.

He was found guilty of second-degree murder in July.

The deceased's husband quickly blamed deficiencies in B.C.'s mental health services for failing their family. Though Whitlock denied having mental health problems, the court heard he believed his mother could cast spells, and that her dog was possessed.

After murdering her, Whitlock told his brother "I killed the witch."

Prior to the crime, Whitlock was found guilty of animal cruelty for beating his German shepherd, Captain, with a baseball bat and leaving the dog to die in a dumpster.

The animal was found covered in cuts and bruises, and died of his injuries the next day. Whitlock was handed 60 days in jail and a lifetime ban on owning animals.

With files from CTV Vancouver's St. John Alexander