A brother and sister have been charged with first-degree murder after an 83-year-old man was killed in his Bonnyville home on Sunday in what police say was a random act.

"There does not appear to have been any previous relationship between the accused and the victim, Alfred Wagner," RCMP said in a news release Thursday. "The police are not seeking any other persons in connection to this case at this time."

A published obituary says Wagner is survived by his wife, four children and nine grandchildren. His funeral is set for Saturday at St. Louis Roman Catholic Church in Bonnyville.

Wagner's body was discovered in his home on Sunday afternoon.

RCMP have located this truck, which was missing from a Bonnyville home where the body of a man was found Sunday. (RCMP) His missing truck was found Monday on the Kehewin Cree Nation reserve, 20 kilometres south of Bonnyville.

A 25-year-old man was arrested near Edmonton on Tuesday. His 20-year-old sister was arrested Wednesday in Edmonton.

Both are from the Bonnyville/Kehewin area, RCMP said.

Each faces one count of first-degree murder.

The man will appear in Bonnyville provincial court on Nov. 1. Police didn't say when the woman would make a court appearance.

Bonnyville is about 240 km northeast of Edmonton.